/kind bug

What this PR does / why we need it:

Prune defaults for CRDs for the OpenAPI V2 CRD controller. This allows the static spec to merge cleanly with the CRD specs (https://github.com/kubernetes/kubernetes/blob/master/staging/src/k8s.io/apiextensions-apiserver/pkg/controller/openapi/controller.go#L230). A DeepEqual check is performed before deciding whether a resource needs to be renamed due to a conflict. The static spec already has its defaults pruned: (https://github.com/kubernetes/kubernetes/blob/master/staging/src/k8s.io/apiserver/pkg/server/routes/openapi.go#L43) The DeepEqual will fail when a resource with defaults pruned is compared to one with defaults intact. This applies for meta types shared between the static spec and CRD specs, so we have "ObjectMeta_v2", "Status_v2", etc.

There is no user facing impact because we currently already prune defaults (later in the chain in the aggregator https://github.com/kubernetes/kubernetes/blob/master/staging/src/k8s.io/kube-aggregator/pkg/controllers/openapi/aggregator/aggregator.go#L188). This just shifts (left?) the pruning earlier in the openapi chain.

I'm not aware of anything that directly uses these OpenAPI schemas published directly from the apiextensions server. SSA builds OpenAPI for CRDs directly from the structural schema and should be unaffected. (https://github.com/kubernetes/kubernetes/blob/master/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/customresource_handler.go#L686)

Which issue(s) this PR fixes:

Fixes #109275

Special notes for your reviewer:

Does this PR introduce a user-facing change?

OpenAPI will no longer duplicate these schemas:
- io.k8s.apimachinery.pkg.apis.meta.v1.DeleteOptions_v2
- io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta_v2
- io.k8s.apimachinery.pkg.apis.meta.v1.OwnerReference_v2
- io.k8s.apimachinery.pkg.apis.meta.v1.StatusDetails_v2
- io.k8s.apimachinery.pkg.apis.meta.v1.Status_v2

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.: