[cern] use cloud group for gitlab-registry images
Drop the google_containers and atomic-system-containers references from gitlab-registry.cern.ch, fetching images directly from the cloud project.
GitLab Registry scheduled maintenance on Wednesday, October 09th 2024 as of 20:00h Geneva time for a period of 1 hour. Further information under https://cern.ch/otg0152540.
Drop the google_containers and atomic-system-containers references from gitlab-registry.cern.ch, fetching images directly from the cloud project.