message: CI: Use ccache in Java builds, but avoid to save artifacts for non-master
diff: @@ -163,6 +163,7 @@ jobs:
  uses: hendrikmuhs/ccache-action@main
  with:
  key: ${{ github.job }}
  + save: ${{ github.ref == 'refs/heads/master' }}
  - name: Build
  shell: bash
  run: make
  