A merge to master re-ran the same compile the PR had just done. Keep
the pull_request trigger and drop the push-to-master one.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
- setup-java v4 is deprecated; use v5 (still with `cache: gradle`,
which works once job containers can reach the runner's cache server).
- Enable Gradle's build cache (org.gradle.caching) so unchanged
compilations are restored from cache instead of re-run.
Co-Authored-By: Claude Opus 5.5 <[email protected]>