Tuist Gradle cache for GitLab CI

Keep Gradle's dependency and wrapper caches across jobs on Tuist Linux and macOS runners. Include the template and reference its snippet before Gradle runs:

include:
  - remote: https://raw.githubusercontent.com/tuist/gradle-cache-gitlab/v1/gradle-cache.yml

test:
  tags: [tuist-linux]
  before_script:
    - !reference [.tuist-gradle-cache, before_script]
  script:
    - ./gradlew test

The snippet attaches a cache volume at $GRADLE_USER_HOME/caches and $GRADLE_USER_HOME/wrapper (~/.gradle when GRADLE_USER_HOME is unset). Set GRADLE_USER_HOME in variables if you use one, and remove cache:paths that restore into those directories. Use !reference rather than extends, which replaces before_script. You can also vendor gradle-cache.yml and use include:local.

Gradle cleans its cache only when its daemon stops, which a CI job rarely reaches. The snippet installs an init script in $GRADLE_USER_HOME/init.d that cleans after every build and removes entries unused for seven days.

Successful default-branch push, schedule and web pipelines save the cache. On runners that are not Tuist runners the snippet does nothing, and if the volume is unavailable the job runs with an empty cache; it never fails the job. SOURCE_COMMIT records its monorepo source.