[skip-ci] Update actions/checkout action to v6

.github/workflows/opendownstream-pr.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: 'Checkout Self'
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         # Because we use pull_request_target, this checks out the code from the default branch, NOT the PR branch
 
       - name: 'Setup Go'
@@ -23,7 +23,7 @@ jobs:
           go-version: 'stable'
 
       - name: 'Checkout forked buildah'
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: 'podmanbot/buildah' # The target repository
           path: 'buildah'                 # Checkout into a sub-directory

.github/workflows/validate.yml

@@ -17,7 +17,7 @@ jobs:
   codespell:
     runs-on: ubuntu-24.04
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: install deps
       # Version of codespell bundled with Ubuntu is way old, so use pip.
       run: pip install --break-system-packages codespell==v2.4.1
@@ -30,7 +30,7 @@ jobs:
       run:
         working-directory: ./common
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 2
     - uses: actions/setup-go@v6
@@ -73,7 +73,7 @@ jobs:
     env:
       GIT_CHECK_EXCLUDE: "./vendor"
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         # By default github actions creates a merge commit which fails the validation,
         # we only must validate the actual commits of the author.
@@ -93,7 +93,7 @@ jobs:
   go-vendor:
     runs-on: ubuntu-24.04
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: actions/setup-go@v6
       with:
         go-version: 1.25.x