This container can be pulled via:
  docker pull registry.opensuse.org/opensuse/factory/zsystems/totest/containers/kubic/etcd:3.5.15-0.3.66
  docker pull registry.opensuse.org/opensuse/factory/zsystems/totest/containers/kubic/etcd:3.5.15-1.3.66

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.