This container can be pulled via:
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/xorg:21
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/xorg:21.1
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/xorg:21.1-5.1
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/xorg:notaskbar

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.