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. See...

- The `IPTablesOwnershipCleanup` feature (KEP-3178) is now GA; kubelet no longer
  creates the `KUBE-MARK-DROP` chain (which has been unused for several releases)
  or the `KUBE-MARK-MASQ` chain (which is now only created by kube-proxy). ([#119374](https://github.com/kubernetes/kubernetes/pull/119374), [@danwinship](https://github.com/danwinship))

  for background information.

### Scheduling

  - Opaque Integer Resources (OIRs) are deprecated and will be removed in
    version 1.9. Extended Resources (ERs) are a drop-in replacement for OIRs. You can use
    any domain name prefix outside of the `kubernetes.io/` domain instead of the
    `pod.alpha.kubernetes.io/opaque-int-resource-` prefix.

## Notable Features

with to go1.18, which introduced significant changes to its garbage collection algorithm. As a result, we observed an increase in memory usage for kube-apiserver in larger an heavily loaded clusters up to ~25% (with the benefit of API call latencies drop by up to 10x on 99th percentiles). If the memory increase is not acceptable for you you can mitigate by setting GOGC env variable (for our tests using GOGC=63 brings memory usage back to original value, although the exact value may depend on usage...

- Fixing issue in Winkernel Proxier - Unexpected active TCP connection drops while horizontally scaling the endpoints for a LoadBalancer Service with External Traffic Policy: Local ([#114039](https://github.com/kubernetes/kubernetes/pull/114039), [@princepereira](https://github.com/princepereira)) [SIG Network]

- `kube-proxy`: Added an option/flag for configuring the `nf_conntrack_tcp_be_liberal` sysctl (in the kernel's netfilter conntrack subsystem).  When enabled, `kube-proxy` will not install the `DROP` rule for invalid conntrack states, which currently breaks users of asymmetric routing. ([#120354](https://github.com/kubernetes/kubernetes/pull/120354), [@aroradaman](https://github.com/aroradaman))

### Feature

- The `apiserver.latency.k8s.io/decode-response-object` annotation was added to the audit log to record the decoding time. ([#121512](https://github.com/kubernetes/kubernetes/pull/121512), [@HirazawaUi](https://github.com/HirazawaUi))
- The drop-in kubelet configuration directory feature has been targeted for Beta. ([#122907](https://github.com/kubernetes/kubernetes/pull/122907), [@sohankunkerkar](https://github.com/sohankunkerkar))

- Fixing issue in Winkernel Proxier - Unexpected active TCP connection drops while horizontally scaling the endpoints for a LoadBalancer Service with External Traffic Policy: Local ([#114038](https://github.com/kubernetes/kubernetes/pull/114038), [@princepereira](https://github.com/princepereira)) [SIG Network]