This container can be pulled via:
  docker pull registry.opensuse.org/opensuse/leap/15.5/images/totest/containers/opensuse/leap-dnf:15.5
  docker pull registry.opensuse.org/opensuse/leap/15.5/images/totest/containers/opensuse/leap-dnf:15.5.4.205

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.