Bump actions/checkout from 5 to 6 (#73)

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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/codeql-analysis.yml

@@ -20,7 +20,7 @@ jobs:
         language: [ 'java' ]
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Set up JDK 17
       uses: actions/setup-java@v5
       with:

.github/workflows/docker-publish.yml

@@ -16,7 +16,7 @@ jobs:
         java-version: ['21', '22', '23']
     runs-on: ubuntu-24.04
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Set up JDK ${{ matrix.java-version }}
       uses: actions/setup-java@v5
       with:
@@ -40,7 +40,7 @@ jobs:
         java-version: ['21', '22', '23']
     if: github.event_name == 'push'
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up JDK ${{ matrix.java-version }}
         uses: actions/setup-java@v5
         with: