Bump actions/checkout in /.github/workflows in the actions group (#238)

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


Updates `actions/checkout` from 5.0.0 to 6.0.0
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](08c6903cd8...1af3b93b68)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
...

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

.github/workflows/unit-tests.yml

@@ -22,7 +22,7 @@ jobs:
          fail-fast: false
       runs-on: ${{ matrix.os }}
       steps:
-         - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+         - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
 
          - name: Run L0 tests.
            run: |