kustomize, so there are a few backwards-incompatible changes, most of which are rare use cases, bug fixes with side effects, or things that have been deprecated for multiple releases already:
  
  - https://github.com/kubernetes-sigs/kustomize/pull/4911: Drop support for a very old, legacy style of patches. patches used to be allowed to be used as an alias for patchesStrategicMerge in kustomize v3. You now have to use patchesStrategicMerge explicitly, or update to the new syntax supported by patches....

- Klog text output now uses JSON as encoding for structs, maps and slices. ([#117687](https://github.com/kubernetes/kubernetes/pull/117687), [@pohly](http...

* [beta] SelfSubjectRulesReview, an API that lets a user see what actions they can perform with a namespace, has been added to the authorization.k8s.io API group. This bulk query is intended to enable UIs to show/hide actions based on the end user, and for users to quickly reason about their own permissions.

  - `alpha` support (guarded by the `ServiceAccountTokenPodNodeInfo` feature gate) for including the node name (and uid, if the node exists) as additional claims in service account tokens it issues which are bound to pods, and `authentication.kubernetes.io/node-name` and `authentication.kubernetes.io/node-uid` extra user info when the token is used to authenticate.

plugin and the `kubernetes.io/enforce-mountable-secrets` annotation are used together with ephemeral containers.

**Note**: This only impacts the cluster if the ServiceAccount admission plugin is used (most cluster should have this on by default as recommended in https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#serviceaccount), the `kubernetes.io/enforce-mountable-secrets` annotation is used by a service account (this annotation is not added by default), and...