This container can be pulled via:
  docker pull registry.opensuse.org/devel/kubic/containers/container/kubic/etcd:3.5.16-0.6.174
  docker pull registry.opensuse.org/devel/kubic/containers/container/kubic/etcd:3.5.16-1.6.174

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.