This container can be pulled via:
  docker pull registry.opensuse.org/isv/rancher/elemental/maintenance/5.5/containers/rancher/elemental-rt-channel:1.4.4
  docker pull registry.opensuse.org/isv/rancher/elemental/maintenance/5.5/containers/rancher/elemental-rt-channel:1.4.4-9.478

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.