returns `nil`. (It now returns a pointer to a zero-valued object, like the real
  clients do.) This will break some downstream unit tests that were testing
  `result == nil` rather than `err != nil`, and in some cases may expose bugs

   ([#123273](https://github.com/kubernetes/kubernetes/pull/123273), ...

* The following deprecated flags were removed from `kube-controller-manager`:

  * `replication-controller-lookup-cache-size`
  * `replicaset-lookup-cache-size`
  * `daemonset-lookup-cache-size`

  Don't use these flags. Using deprecated flags causes the server to print a warning. Using a removed flag causes the server to abort the startup.

* The following deprecated flags were removed from `kubelet`:

  managed by the GLBC Ingress Controller. This can cause the health checks to start failing,
  requiring you to reapply the manual edits.
  * This issue does not affect clusters that were already running Kubernetes v1.6.4 or higher.
  * This issue does not affect Health Checks that were left in the configuration
    [originally set by the GLBC Ingress Controller](https://github.com/kubernetes/ingress-nginx/tree/0.9.0-beta.1/controllers/gce#health-checks).

## Changelog since v1.22.8

## Changes by Kind

### Bug or Regression

* Fix a bug in GCE multizonal clusters where PersistentVolumes were sometimes created in zones without nodes. ([#52322](https://github.com/kubernetes/kubernetes/pull/52322), [@davidz627](https://github.com/davidz627))

SIG Node iterated on the ability to support more workloads with better performance and improved reliability.  Alpha features were improved around hardware accelerator support, device plugins enablement, and cpu pinning policies to enable us to graduate these features to beta in a future release.  In addition, a number of reliability and performance enhancements were made across the node to help operators in production.

### OpenStack

- Modified command line errors (for example, `kubectl list` -> `unknown command`) that were printed as log message with escaped line breaks instead of a multi-line plain text, making the error hard to read. ([#107044](https://github.com/kubernetes/kubernetes/pull/107044), [@pohly](https://github.com/pohly))

### SIG Network

For 1.13, the areas of focus were in IPv6, DNS improvements and some smaller items:
CoreDNS is now the default cluster DNS passing all of the scale/resource usage tests

- Fixed a regression that could incorrectly reject pods with OutOfCpu errors if they were rapidly scheduled after other pods were reported as complete in the API. The Kubelet now waits to report the phase of a pod as terminal in the API until all running containers are guaranteed to have stopped and no new containers can be started.  Short-lived pods may take...