- https://github.com/kubernetes-sigs/kustomize/issues/4731: Remove a potential build-time side-effect in ConfigMapGenerator and SecretGenerator, which loaded values from the local environment under some circumstances, breaking kustomize build's side-effect-free promise. While this behavior was never intended, we deprecated it and are announcing it as a breaking change since it existed for a long time. See also the Eschewed...

[Sig API Machinery]: https://github.com/kubernetes/community/tree/master/sig-api-machinery

### SIG Apps

    - [Promoted CRD Validation Expression Language to Beta](#promoted-crd-validation-expression-language-to-beta)
    - [Promoted Server Side Unknown Field Validation to Beta](#promoted-server-side-unknown-field-validation-to-beta)
    - [Introduced KMS v2](#introduced-kms-v2)
    - [Kube-proxy images are now based on distroless images](#kube-proxy-images-are-now-based-on-distroless-images)

- Added `client-go` support for upgrading subresource fields from client-side to server-side management. ([#123484](https://github.com/kubernetes/kubernetes/pull/123484), [@erikgb](https://github.com/erikgb))

- Fixed bugs in handling of server-side apply, create, and update API requests for objects containing duplicate items in keyed lists.
  - A `create` or `update` API request with duplicate items in a keyed list no longer wipes out managedFields. Examples include env var entries with the same name, or port entries with the same containerPort in a pod spec.

- For `kubectl`, `--server-side` now migrates ownership of all fields used by client-side-apply to the specified `--fieldmanager`. This prevents fields previously specified using kubectl from being able to live outside of server-side-apply's management and become undeleteable. ([#112905](https://github.com/kubernetes/kubernetes/pull/112905), [@alexzielenski](https://github.com/alexzielenski))...