Bump actions/checkout from 5 to 6 (#57)

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
...

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

Author: dependabot[bot]

.github/workflows/continuousIntegration.yml

@@ -17,7 +17,7 @@ jobs:
         with:
           access_token: ${{ github.token }}
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: PHP ${{ matrix.php }} 
         uses: shivammathur/setup-php@v2