- Dropped support for `certificates/v1beta1` `CertificateSigningRequest` in `kubectl`. ([#134782](https://github.com/kubernetes/kubernetes/pull/134782), [@scaliby](https://github.com/scaliby))
- Dropped support for `discovery/v1beta1` `EndpointSlice` in `kubectl`. ([#134913](https://github.com/kubernetes/kubernetes/pull/134913), [@scaliby](https://github.com/scaliby))

- Introduced API type `coordination.k8s.io/v1beta1/LeaseCandidate`
  `CoordinatedLeaderElection` feature moves to Beta ([#130751](https://github.com/kubernetes/kubernetes/pull/130751), [@Jefftree](https://github.com/Jefftree)) [SIG API Machinery, Etcd and Testing]

- Introduced the `admissionregistration.k8s.io/v1beta1/MutatingAdmissionPolicy` API type. To enable, enable the `MutatingAdmissionPolicy` feature gate (which was off by default) and set `--runtime-config=admissionregistration.k8s.io/v1beta1=true` on the kube-apiserver. 

- Config.k8s.io.flagz API is graduated to v1beta1 ([#137174](https://github.com/kubernetes/kubernetes/pull/137174), [@richabanker](https://github.com/richabanker)) [SIG API Machinery, Instrumentation, Node, Scheduling and Testing]

### Bug or Regression

- Kubeadm: fixed bug where v1beta3's ClusterConfiguration.APIServer.TimeoutForControlPlane is not respected in newer versions of kubeadm where v1beta4 is the default. ([#133755](https://github.com/kubernetes/kubernetes/pull/133755), [@HirazawaUi](https://github.com/HirazawaUi)) [SIG Cluster Lifecycle]