Bump actions/labeler from 4 to 5

Bumps [actions/labeler](https://github.com/actions/labeler) from 4 to 5.
- [Release notes](https://github.com/actions/labeler/releases)
- [Commits](https://github.com/actions/labeler/compare/v4...v5)

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

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

.github/workflows/labels.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.repository_owner == 'NixOS'
     steps:
-    - uses: actions/labeler@v4
+    - uses: actions/labeler@v5
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
         sync-labels: false