chore(deps): Bump actions/checkout in the actions-infrastructure group (#535)

Bumps the actions-infrastructure 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: actions-infrastructure
...

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

Author: dependabot[bot]

.github/workflows/validate_datasets.yml

@@ -28,7 +28,7 @@ jobs:
       spec_pr: ${{ steps.find-pr.outputs.spec_pr }}
       val_pr: ${{ steps.find-pr.outputs.val_pr }}
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0  # Get full history for commit message scanning