Update swagger v2 test data from Kubernetes v1.8 to v1.35

## Summary

The swagger v2 test data in `pkg/util/proto/testdata/` (`swagger.json`, `swagger_next.json`) still references `apps/v1beta1` models from Kubernetes v1.8.0. These should be updated to use GA `apps/v1` models from a current release.

Draft PR: #581

Raised in https://github.com/kubernetes/kube-openapi/pull/579#discussion_r2948598747 by @Jefftree