This container can be pulled via:
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/bci/spack:0.23
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/bci/spack:0.23.0
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/bci/spack:0.23.0-6.12

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.