Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/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
...

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

Author: dependabot[bot]

.github/workflows/codeql.yml

@@ -53,7 +53,7 @@ jobs:
         # your codebase is analyzed, see https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/codeql-code-scanning-for-compiled-languages
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       # Add any setup steps before running the `github/codeql-action/init` action.
       # This includes steps like installing compilers or runtimes (`actions/setup-node`

.github/workflows/deploy-docs.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         fetch-depth: 5
     - name: Set Up Gradle

.github/workflows/merge-dependabot-pr.yml

@@ -14,7 +14,7 @@ jobs:
     if: github.event.pull_request.user.login == 'dependabot[bot]'
     steps:
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           show-progress: false
           ref: ${{ github.event.pull_request.head.sha }}