Bump actions/labeler from 4 to 6

Bumps [actions/labeler](https://github.com/actions/labeler) from 4 to 6.
- [Release notes](https://github.com/actions/labeler/releases)
- [Commits](actions/labeler@v4...v6)

---
updated-dependencies:
- dependency-name: actions/labeler
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/pr-tools.yml

@@ -27,7 +27,7 @@ jobs:
         uses: actions/checkout@v4 # https://github.com/actions/checkout/tree/main#usage
 
       # https://github.com/actions/labeler#usage
-      - uses: actions/labeler@v4
+      - uses: actions/labeler@v6
         with:
           # https://github.com/actions/labeler#inputs
           configuration-path: .github/labeler.yml