This container can be pulled via:
  docker pull registry.opensuse.org/home/cobbler-project/github-ci/containers/cobbler-test-github:latest
  docker pull registry.opensuse.org/home/cobbler-project/github-ci/containers/cobbler-test-github:main
  docker pull registry.opensuse.org/home/cobbler-project/github-ci/containers/cobbler-test-github:main.20.1

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.