Bump actions/cache from 4 to 5 in /check-copyrights

Bumps [actions/cache](https://github.com/actions/cache) from 4 to 5.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v4...v5)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

check-copyrights/action.yml

@@ -67,7 +67,7 @@ runs:
   steps:
     - name: Cache RAT
       id: cache
-      uses: actions/cache@v4
+      uses: actions/cache@v5
       with:
         path: ${{ github.action_path }}/apache-rat-${{ inputs.version }}
         key: apache-rat-${{ inputs.version }}