Bump actions/checkout from 5 to 6 in the github-actions group

Bumps the github-actions group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `actions/checkout` from 5 to 6
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions
...

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

Author: dependabot[bot]

.github/workflows/markdown-links.yml

@@ -13,5 +13,5 @@ jobs:
   markdown-link-check:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: gaurav-nelson/github-action-markdown-link-check@v1

.github/workflows/test.yml

@@ -36,7 +36,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Substitute Python version
         run: |
@@ -66,7 +66,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up Python
         uses: actions/setup-python@v6
@@ -134,7 +134,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Remove Pipfile.lock
         run: rm Pipfile.lock
@@ -173,7 +173,7 @@ jobs:
 
     steps:
       - name: Check out source repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up Python environment
         uses: actions/setup-python@v6
@@ -190,7 +190,7 @@ jobs:
 
     steps:
       - name: Check out source repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Analyze shell scripts
         uses: bewuethr/shellcheck-action@v2
@@ -216,7 +216,7 @@ jobs:
           relative_workflow_with_ref="${GITHUB_WORKFLOW_REF#"$GITHUB_REPOSITORY/"}"
           echo "WORKFLOW_PATH=${relative_workflow_with_ref%@*}" >> "$GITHUB_ENV"
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           sparse-checkout: ${{ env.WORKFLOW_PATH }}