package and packagemetadata SMD and SSA are broken after k8s.io 0.36 module updates

**What steps did you take:**

Server-side apply (`kubectl apply --server-side`) against a `Package` or `PackageMetadata` object.

```
kubectl apply --server-side --field-manager=repro -f - <<'EOF'
apiVersion: data.packaging.carvel.dev/v1alpha1
kind: PackageMetadata
metadata:
name: repro.example.com
namespace: default
spec:
displayName: "repro"
EOF
```

**What happened:**

```
Error from server: failed to create manager for existing fields: failed to convert new object
(...) to smd typed: no corresponding type for data.packaging.carvel.dev/v1alpha1, Kind=PackageMetadata
```

**What did you expect:**

`packagemetadata.data.packaging.carvel.dev/repro.example.com serverside-applied`

(SSA works as it did in v0.59.8 and prior.)

**Anything else you would like to add:**

In addition to SSA not working, kapp-controller can be seen logging `[SHOULD NOT HAPPEN] failed to update managedFields` for existing `packages` and `packagemetadatas`, with the practical effect that `.metadata.managedFields` on these objects goes stale. Structured merge diff, which SSA relies on, is no longer working for these types.

Bisected the issue to v0.60.0 (last good: v0.59.8). It's actually a side effect of the k8s.io module bumps in v0.60.0 (k8s.io/api, k8s.io/apimachinery, k8s.io/apiserver, k8s.io/client-go v0.30.1 bumped to v0.36.0): https://github.com/carvel-dev/kapp-controller/pull/1829

Types in `pkg/apiserver/apis/datapackaging/v1alpha1` do not implement the new opt-in `OpenAPIModelNamer` convention (see https://github.com/kubernetes/kubernetes/pull/131755, https://github.com/kubernetes/kube-openapi/pull/563, https://github.com/kubernetes/kube-openapi/pull/537), which is a [known source source of issues](https://github.com/kubernetes/kubernetes/issues/138247) with this k8s.io update, e.g. https://github.com/kubernetes-sigs/aws-load-balancer-controller/issues/4543 and https://github.com/karmada-io/karmada/pull/7255

More about the OpenAPI issue in this gist: https://gist.github.com/chappjc/abadce8b5abbfcfd677bd3688ad81e28#demo-the-served-openapi-document

**Environment:**

- kapp Controller version: v0.60.4
- Kubernetes version: v1.34.9

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Start in pkg/apiserver/apis/datapackaging/v1alpha1 and read the OpenAPIModelNamer convention introduced by the k8s.io module updates. Reproduce the failure with the documented kubectl server-side apply command, then verify that Package and PackageMetadata support structured merge diff, server-side apply, and managedFields updates without errors.

Written by the indexing model from the issue text.