Think about HA (running several replicas) and enabling topology-aware routing for the deployed registries

[ialidzhikov]

How to categorize this issue?

/area high-availability
/kind enhancement

What would you like to be added:
This issue is extracted from #3:

Technically, it works. Such feature will allow us to reduce the cross-zone traffic. We could expose it as config option of the registry-cache extension. We agreed to wait for kubernetes/kubernetes#121060 --> kubernetes/kubernetes#123487 to have a deterministic topology-aware traffic routing in the Shoot cluster (the GRM's endpointslices webhook currently is not enabled for Shoots). For more details on why we have to wait for this PR, see kubernetes/kubernetes#113731.

Why is this needed:
To reduce cross-zonal traffic costs and latency.