This container can be pulled via:
  docker pull registry.opensuse.org/virtualization/containerfile/kubevirt/virt-synchronization-controller:1.6.3
  docker pull registry.opensuse.org/virtualization/containerfile/kubevirt/virt-synchronization-controller:1.6.3-Virt.1699.212.1
  docker pull registry.opensuse.org/virtualization/containerfile/kubevirt/virt-synchronization-controller:1.6.3.Virt.1699.1.3

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.