This container can be pulled via:
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/cosign:3
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/cosign:3.1
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/cosign:3.1.3
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/cosign:3.1.3-28.31

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.