This container can be pulled via:
  docker pull registry.opensuse.org/network/cluster/containers/containers-15.6/warewulf-rke2-base:latest
  docker pull registry.opensuse.org/network/cluster/containers/containers-15.6/warewulf-rke2-base:v1.30.5_rke2r1

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.