diff --git a/.github/workflows/cmake.yml b/.github/workflows/cmake.yml
index 1c71dd20be..dbe600d572 100644
--- a/.github/workflows/cmake.yml
+++ b/.github/workflows/cmake.yml
@@ -4,7 +4,7 @@ jobs:
   cmake-linux:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       run: |
         sudo apt update
@@ -31,7 +31,7 @@ jobs:
   cmake-linux-with-options:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       run: |
         sudo apt update
@@ -56,7 +56,7 @@ jobs:
   cmake-win:
     runs-on: windows-2022
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Cache
       uses: hendrikmuhs/ccache-action@v1.2
       with:
@@ -93,7 +93,7 @@ jobs:
   cmake-win-dynamic-runtime:
     runs-on: windows-2022
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Cache
       uses: hendrikmuhs/ccache-action@v1.2
       with:
@@ -130,7 +130,7 @@ jobs:
   cmake-win-with-options:
     runs-on: windows-2022
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Cache
       uses: hendrikmuhs/ccache-action@v1.2
       with:
@@ -165,7 +165,7 @@ jobs:
   cmake-macos:
     runs-on: macos-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       env:
         HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK: 1
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index 61e7762fe6..6525704c0a 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -17,7 +17,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
diff --git a/.github/workflows/copyrights.yml b/.github/workflows/copyrights.yml
index dfaaa30053..776cf32a58 100644
--- a/.github/workflows/copyrights.yml
+++ b/.github/workflows/copyrights.yml
@@ -7,7 +7,7 @@ jobs:
   copyrights:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Check
       run: |
         ./tools/check_copyrights.sh
diff --git a/.github/workflows/coveralls.yml b/.github/workflows/coveralls.yml
index 3e8e8304c4..9f3405c22e 100644
--- a/.github/workflows/coveralls.yml
+++ b/.github/workflows/coveralls.yml
@@ -8,7 +8,7 @@ jobs:
   coverage:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       run: |
         sudo apt update
diff --git a/.github/workflows/devenv-images.yml b/.github/workflows/devenv-images.yml
index 15ec82cb96..d28759a30f 100644
--- a/.github/workflows/devenv-images.yml
+++ b/.github/workflows/devenv-images.yml
@@ -14,7 +14,7 @@ jobs:
       matrix:
         tag: [lunar, mantic, noble]
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Build CI images
       working-directory: dockerfiles
       run: |
diff --git a/.github/workflows/doxygen.yml b/.github/workflows/doxygen.yml
index 5ef3aea0d3..3f9875100a 100644
--- a/.github/workflows/doxygen.yml
+++ b/.github/workflows/doxygen.yml
@@ -4,7 +4,7 @@ jobs:
   docs:
     runs-on: macos-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       env:
         HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK: 1
@@ -22,7 +22,7 @@ jobs:
   header-docs:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Check
       run: |
         ./tools/check_all_header_docs.sh
diff --git a/.github/workflows/filelists.yml b/.github/workflows/filelists.yml
index 89dcfd2287..a5ea31b078 100644
--- a/.github/workflows/filelists.yml
+++ b/.github/workflows/filelists.yml
@@ -4,7 +4,7 @@ jobs:
   filelists:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       run: |
         sudo apt update
diff --git a/.github/workflows/generated-headers.yml b/.github/workflows/generated-headers.yml
index d2f8cabda3..2f84389034 100644
--- a/.github/workflows/generated-headers.yml
+++ b/.github/workflows/generated-headers.yml
@@ -7,7 +7,7 @@ jobs:
   filelists:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       run: |
         sudo apt update
diff --git a/.github/workflows/headers.yml b/.github/workflows/headers.yml
index 564ced713d..eb9809c7cf 100644
--- a/.github/workflows/headers.yml
+++ b/.github/workflows/headers.yml
@@ -4,7 +4,7 @@ jobs:
   headers:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       run: |
         sudo apt update
diff --git a/.github/workflows/linux-full-tests.yml b/.github/workflows/linux-full-tests.yml
index 527dc395e3..bd8e2cb7f0 100644
--- a/.github/workflows/linux-full-tests.yml
+++ b/.github/workflows/linux-full-tests.yml
@@ -195,7 +195,7 @@ jobs:
             configureflags: --enable-null-as-functions
     container: ghcr.io/lballabio/quantlib-devenv:${{ matrix.tag }}
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Compiler version
       run: |
         ${{ matrix.cc }} --version
diff --git a/.github/workflows/linux-nondefault.yml b/.github/workflows/linux-nondefault.yml
index ce05c918d3..0c73dbc3c9 100644
--- a/.github/workflows/linux-nondefault.yml
+++ b/.github/workflows/linux-nondefault.yml
@@ -154,7 +154,7 @@ jobs:
             configureflags: --enable-openmp
     container: ghcr.io/lballabio/quantlib-devenv:${{ matrix.tag }}
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Compiler version
       run: |
         ${{ matrix.cc }} --version
diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 32f8632397..032293cce6 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -185,7 +185,7 @@ jobs:
             tests: true
     container: ghcr.io/lballabio/quantlib-devenv:${{ matrix.tag }}
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Cache
       uses: hendrikmuhs/ccache-action@v1.2
       with:
diff --git a/.github/workflows/macos-nondefault.yml b/.github/workflows/macos-nondefault.yml
index e19f7cda3b..d9b4bce2df 100644
--- a/.github/workflows/macos-nondefault.yml
+++ b/.github/workflows/macos-nondefault.yml
@@ -23,7 +23,7 @@ jobs:
             cxxflags: "-std=c++17"
             configureflags: --disable-std-function --disable-std-tuple --enable-std-pointers --enable-std-optional --enable-std-any
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       env:
         HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK: 1
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 780d6b2430..c813ca0163 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -12,7 +12,7 @@ jobs:
           - os: [macos-13]
             shortname: default-13
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       env:
         HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK: 1
diff --git a/.github/workflows/misspell.yml b/.github/workflows/misspell.yml
index 1c7072e593..75cee11917 100644
--- a/.github/workflows/misspell.yml
+++ b/.github/workflows/misspell.yml
@@ -7,7 +7,7 @@ jobs:
   check:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: sobolevn/misspell-fixer-action@master
     - uses: peter-evans/create-pull-request@v6
       with:
diff --git a/.github/workflows/msvc-all-configs.yml b/.github/workflows/msvc-all-configs.yml
index 7ce9f7cfc9..833cedd04e 100644
--- a/.github/workflows/msvc-all-configs.yml
+++ b/.github/workflows/msvc-all-configs.yml
@@ -23,7 +23,7 @@ jobs:
             toolset: "14.3"
             boost_version: 84
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup MSVC++ environment
       uses: ilammy/msvc-dev-cmd@v1
       with:
diff --git a/.github/workflows/msvc-analysis.yml b/.github/workflows/msvc-analysis.yml
index 237d5df427..8df2e94cb5 100644
--- a/.github/workflows/msvc-analysis.yml
+++ b/.github/workflows/msvc-analysis.yml
@@ -16,7 +16,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Setup
         run: |
diff --git a/.github/workflows/msvc-nondefault.yml b/.github/workflows/msvc-nondefault.yml
index 3f79139111..8c909de232 100644
--- a/.github/workflows/msvc-nondefault.yml
+++ b/.github/workflows/msvc-nondefault.yml
@@ -22,7 +22,7 @@ jobs:
             toolset: "14.3"
             boost_version: 84
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup MSVC++ environment
       uses: ilammy/msvc-dev-cmd@v1
       with:
diff --git a/.github/workflows/msvc.yml b/.github/workflows/msvc.yml
index 67e618b096..9effad1b5e 100644
--- a/.github/workflows/msvc.yml
+++ b/.github/workflows/msvc.yml
@@ -18,7 +18,7 @@ jobs:
             toolset: "14.3"
             boost_version: 84
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup MSVC++ environment
       uses: ilammy/msvc-dev-cmd@v1
       with:
diff --git a/.github/workflows/sanitizer.yml b/.github/workflows/sanitizer.yml
index 2d75438ce4..c521a675ce 100644
--- a/.github/workflows/sanitizer.yml
+++ b/.github/workflows/sanitizer.yml
@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     container: ghcr.io/lballabio/quantlib-devenv:rolling
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Compiler version
       run: |
         gcc --version
@@ -27,7 +27,7 @@ jobs:
     runs-on: ubuntu-latest
     container: ghcr.io/lballabio/quantlib-devenv:rolling
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Compiler version
       run: |
         gcc --version
diff --git a/.github/workflows/test-times.yml b/.github/workflows/test-times.yml
index 49492465ef..f629789cea 100644
--- a/.github/workflows/test-times.yml
+++ b/.github/workflows/test-times.yml
@@ -4,7 +4,7 @@ jobs:
   check-test-times:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Cache
       uses: hendrikmuhs/ccache-action@v1.2
       with:
diff --git a/.github/workflows/tidy.yml b/.github/workflows/tidy.yml
index 01a6aa8368..d14c3a246c 100644
--- a/.github/workflows/tidy.yml
+++ b/.github/workflows/tidy.yml
@@ -7,7 +7,7 @@ jobs:
   check:
     runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Setup
       run: |
         sudo apt-get update