## Changes by Kind

### API Change

- Aggregated discovery now returns `responseKind: {}` for resources which are missing group/version/kind information, to ensure compatibility with v0.26.0-v0.26.3 clients. ([#119835](https://github.com/kubernetes/kubernetes/pull/119835), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Testing]

### Feature

- NONE ([#124326](https://github.com/kubernetes/kubernetes/pull/124326), [@ritazh](https://github.com/ritazh)) [SIG Auth]
- OpenAPI V2 will no longer publish aggregated apiserver OpenAPI for group-versions not matching the APIService specified group version ([#123625](https://github.com/kubernetes/kubernetes/pull/123625), [@Jefftree](https://github.com/Jefftree)) [SIG API Machinery and Testing]

## Dependencies

### Added

`kubeadm`: a separate "super-admin.conf" file is now deployed. The User in `admin.conf` is now bound to a new RBAC Group `kubeadm:cluster-admins` that has `cluster-admin` `ClusterRole` access. The User in `super-admin.conf` is now bound to the `system:masters` built-in super-powers / break-glass Group that can bypass RBAC. Before this change, the default `admin.conf` was bound to `system:masters` Group, which was undesired. Executing `kubeadm init phase kubeconfig all` or just `kubeadm init` will now generate...

- Log messages and metrics for the watch cache are now keyed by `<resource>.<group>` instead of `go` struct type. This means e.g. that `*v1.Pod` becomes `pods`. Additionally, resources that come from `CustomResourceDefinitions` are displayed as the correct resource and group, instead of `*unstructured.Unstructured`. ([#111807](https://github.com/kubernetes/kubernetes/pull/111807), [@ncdc](https://github.com/ncdc))