Tuist module cache for GitLab CI

Keep Tuist's local cache across jobs on Tuist macOS runners: module cache binaries, along with compiled manifests, plugins and selective testing results. Include the template and reference its snippet before your tuist commands:

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

test:
  tags: [tuist-macos]
  before_script:
    - !reference [.tuist-module-cache, before_script]
  script:
    - tuist generate --no-open
    - tuist test

Use !reference rather than extends: extends replaces before_script, so it cannot combine this snippet with the Xcode cache's or your own. You can also vendor module-cache.yml and use include:local.

The snippet sets TUIST_XDG_CACHE_HOME to the cache and TUIST_CACHE_MAX_BYTES to its share of the storage, so the Tuist CLI evicts the least recently used binaries before the cache fills up.

Tuist does not yet verify GitLab jobs for its built-in caches, so on GitLab the cache starts empty and is not saved. Once Tuist verifies GitLab jobs, the same snippet starts saving with no pipeline change.

On runners that are not Tuist macOS runners the snippet does nothing. If the runner could not restore the cache, it warns and the job runs with an empty one; it never fails the job. SOURCE_COMMIT records its monorepo source.