Move the registry service to the zonal clusters

I suggest that we move the registry node pools to the zonal clusters. This will give us a bit more isolation for the service and will help us to determine zonal related outages more quickly for the service.

Resolution

Change production#3095 (closed) is now complete, the current configuration:

• Regional cluster: 1 node that is running workloads in the canary namespace, registry has been removed from the main stage
• Zonal clusters: currently scaled up to 3 nodes each in the new registry node pools

We are using registry.gitlab.com for the internal API endpoint like we were in VMs, until https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/12029 is resolved.