Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/black.yml

@@ -17,7 +17,7 @@ jobs:
     black:
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
 
         -   uses: actions/setup-python@v4
             with:

.github/workflows/build-docs.yml

@@ -23,7 +23,7 @@ jobs:
         if: github.repository == 'nilearn/nilearn'
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   name: Check whether the citation metadata from CITATION.cff is valid
             uses: citation-file-format/cffconvert-github-action@2.0.0
             with:
@@ -53,7 +53,7 @@ jobs:
                 restore-keys: |
                     source-cache-${{ runner.os }}
         -   name: Checkout nilearn
-            uses: actions/checkout@v3
+            uses: actions/checkout@v4
             with:
           # If pull request, checkout HEAD commit with all commit history
                 ref: ${{ github.event.pull_request.head.sha }}

.github/workflows/codespell.yml

@@ -13,5 +13,5 @@ jobs:
         runs-on: ubuntu-latest
 
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   uses: codespell-project/actions-codespell@master

.github/workflows/detect_test_pollution.yml

@@ -37,7 +37,7 @@ jobs:
         runs-on: ubuntu-latest
 
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
 
         -   name: Setup python
             uses: actions/setup-python@v4

.github/workflows/f_strings.yml

@@ -17,7 +17,7 @@ jobs:
     f_strings:
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
 
         -   uses: actions/setup-python@v4
             with:

.github/workflows/flake8.yml

@@ -23,7 +23,7 @@ jobs:
                 shell: bash
 
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
 
         -   name: Setup python
             uses: actions/setup-python@v4

.github/workflows/isort.yml

@@ -17,7 +17,7 @@ jobs:
     isort:
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
 
         -   uses: actions/setup-python@v4
             with:

.github/workflows/testing.yml

@@ -20,7 +20,7 @@ jobs:
         env:
             MIN_REQUIREMENTS: true
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   uses: actions/setup-python@v4
             with:
                 python-version: '3.7'
@@ -52,7 +52,7 @@ jobs:
             MIN_REQUIREMENTS: true
             MATPLOTLIB: true
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   uses: actions/setup-python@v4
             with:
                 python-version: '3.7'
@@ -83,7 +83,7 @@ jobs:
             run:
                 shell: bash
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   uses: actions/setup-python@v4
             with:
                 python-version: ${{ matrix.python-version }}
@@ -124,7 +124,7 @@ jobs:
             run:
                 shell: bash
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   uses: actions/setup-python@v4
             with:
                 python-version: ${{ matrix.python-version }}

.github/workflows/testing_install.yml

@@ -27,7 +27,7 @@ jobs:
             run:
                 shell: bash
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   name: Setup python
             uses: actions/setup-python@v4
             with:

.github/workflows/trigger-hosting.yml

@@ -17,7 +17,7 @@ jobs:
         if: github.repository == 'nilearn/nilearn' && github.event.workflow_run.conclusion == 'success'
         steps:
         -   name: Checkout nilearn
-            uses: actions/checkout@v3
+            uses: actions/checkout@v4
 
         -   name: Trigger hosting jobs
             run: bash build_tools/github/trigger_hosting.sh

.github/workflows/update_authors.yml

@@ -16,7 +16,7 @@ jobs:
         if: github.repository == 'nilearn/nilearn'
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
 
         -   uses: actions/setup-python@v4
             with:

.github/workflows/update_precommit_hooks.yml

@@ -32,7 +32,7 @@ jobs:
         runs-on: ubuntu-latest
         steps:
         -   name: Checkout repo
-            uses: actions/checkout@v3
+            uses: actions/checkout@v4
         -   name: Set up Python
             uses: actions/setup-python@v4
             with: