Added `validationActions` to `ValidatingAdmissionPolicyBinding`, enabling validation failures to be handled by any combination of the warn, audit and deny enforcement actions. ([#115973](https://github.com/kubernetes/kubernetes/pull/115973), [@jpbetz](https://github.com/jpbetz))

- Fixed a regression in kube-proxy where it might refuse to start if given
  single-stack IPv6 configuration options on a node that has both IPv4 and
  IPv6 IPs. ([#121008](https://github.com/kubernetes/kubernetes/pull/121008), [@danwinship](https://github.com/danwinship)) [SIG Network]

- Introduced a feature gate mechanism to `client-go`. Depending on the actual implementation, users can control features via environmental variables or command line options. ([#122555](https://github.com/kubernetes/kubernetes/pull/122555), [@p0lyn0mial](https://github.com/p0lyn0mial))

- Added options for configuring `nf_conntrack_udp_timeout`, and `nf_conntrack_udp_timeout_stream` variables of netfilter conntrack subsystem. ([#120808](https://github.com/kubernetes/kubernetes/pull/120808), [@aroradaman](https://github.com/aroradaman))

- Added a `--topology-manager-policy-options` flag to the kubelet to support fine tuning the topology manager policies. The first policy option, `prefer-closest-numa-nodes`, allows these policies to favor sets of NUMA nodes with shorter distance between nodes when making admission decisions....