Add OWNERS validation for kubeflow/hub

[jonburdo]

approvers for kubeflow hub should also be in kubeflow-hub-team in kubeflow/internal-acls

See kubeflow/model-registry#2182 (review)

We have a checker in model-registry for this: https://github.com/kubeflow/model-registry/blob/main/.github/workflows/check-owners.yml

A good first step would be adding that checker to this repo and adjusting it to look at kubeflow/hub/OWNERS.

Perhaps it should also warn if out of sync with the base OWNERS in model-registry?

[muhammadjunaid8047]

Hi @jonburdo, Could you please assign this issue to me?
/assign