Draft: Migrate continuous integration to Eclipse

We've moved the main Oniro git repository over to Eclipse GitLab and thus we can start the process of re-enabling and adjusting continuous integration.

We can operate CI with the use of Booting repositories as help. We obviously use the repositories that are not yet migrated. We also use the docker registry operated by the Booting instance. During the transition we've disabled documentation aggregation features, as those rely on the docs repository having been migrated and that has not occurred yet.