- When registering with a 1.17+ API server, MutatingWebhookConfiguration and ValidatingWebhookConfiguration objects can now request that only `v1` AdmissionReview requests be sent to them. Previously, webhooks were required to support receiving `v1beta1` AdmissionReview requests as well for compatibility with API servers <= 1.15.

- Fixed an issue with the `garbagecollection` controller registering duplicate event handlers if discovery requests failed. ([#117992](https://github.com/kubernetes/kubernetes/pull/117992), [@liggitt](https://github.com/liggitt))

TokenReview](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.13/#tokenreview-v1-authentication-k8s-io) for the new tokens for improved scoping. Under audit logging, the new alpha-level "dynamic audit configuration" adds support for [dynamically registering webhooks to receive a stream of audit events](https://kubernetes.io/docs/tasks/debug/debug-cluster/audit/#webhook-backend). Finally, we've enhanced secrets protection by graduating [etcd encryption](https://kubernetes.io/docs/tasks/administer-c...

  So, if you want to just keep the existing behavior, you can register `ClusterEventWithHint` with no `QueueingHintFn` in it. 

- Improved the efficiency of NodeAdded QueueingHint by registering UpdateNodeTaint event for plugins that have NodeAdded event but don't have UpdateNodeTaint event. This ensures better requeuing efficiency and prevents Pods from being stuck in the unschedulable pod pool.

* Fix kubectl describe for pods with controllerRef  ([#45467](https://github.com/kubernetes/kubernetes/pull/45467), [@ddysher](https://github.com/ddysher))
* Skip errors when unregistering juju kubernetes-workers ([#48144](https://github.com/kubernetes/kubernetes/pull/48144), [@ktsakalozos](https://github.com/ktsakalozos))