GitHub Sync Helpers 🔄

main_from_repository.sh force-pushes the source repository’s main onto the current repository’s main. The 🔄 Sync main job of entry-push-latest.yml runs it on every push.

The push needs the secret CI_SYNC_MAIN_TOKEN, see secrets.md. The source repository and the switch to disable the sync are the repository variable CI_SYNC_MAIN_SOURCE_REPOSITORY, see configuration.md.