* Fixes a bug in openapi published for custom resources using x-kubernetes-preserve-unknown-fields extensions, so that kubectl will allow sending unknown fields for that portion of the object. ([#79636](https://github.com/kubernetes/kubernetes/pull/79636), [@liggitt](https://github.com/liggitt))

## Changelog since v1.3.6

### Other notable changes

* AWS: Add ap-south-1 to list of known AWS regions ([#28428](https://github.com/kubernetes/kubernetes/pull/28428), [@justinsb](https://github.com/justinsb))
* Back porting critical vSphere bug fixes to release 1.3 ([#31993](https://github.com/kubernetes/kubernetes/pull/31993), [@dagnello](https://github.com/dagnello))

  * More expressive node affinity syntax, and support for “soft” node affinity.
Node selectors (to constrain pods to schedule on a subset of nodes) now support
the operators {<code>In, NotIn, Exists, DoesNotExist, Gt, Lt</code>}  instead of just conjunction of exact match on node label values. In
addition, we’ve introduced a new “soft” kind of node selector that is just a

- client-go: `PortForwarder.GetPorts()` now contain correct local port if no local port was initially specified when setting up the port forwarder ([#73676](https://github.com/kubernetes/kubernetes/pull/73676), [@martin-helmich](https://github.com/martin-helmich))
- Fixed an issue with missing `apiVersion/kind` in object data sent to admission webhooks ([#74448](https://github.com/kubernetes/kubernetes/pull/74448), [@liggitt](https://github.com/liggitt))