This container can be pulled via:
  docker pull registry.opensuse.org/home/cobbler-project/github-ci/containers/cobbler-test-github:uyuni-master
  docker pull registry.opensuse.org/home/cobbler-project/github-ci/containers/cobbler-test-github:uyuni-master.3.1

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.