chore(deps): bump actions/checkout from 5 to 6 in the gh_actions group

Bumps the gh_actions 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: gh_actions
...

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

Author: dependabot[bot]

.github/workflows/sync-labels.yml

@@ -12,7 +12,7 @@ jobs:
   sync-labels:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: micnncim/action-label-syncer@v1.3.0
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}