- Added a new Priority and Fairness metric `apiserver_flowcontrol_request_dispatch_no_accommodation_total` to track the number of times a request dispatch attempt results in a no-accommodation status due to lack of available seats. ([#106629](https://github.com/kubernetes/kubernetes/pull/106629), [@tkashem](https://github.com/tkashem))

- Track the number of Pods with a Ready condition in Job status. The feature is alpha and needs the feature gate JobReadyPods to be enabled. ([#104915](https://github.com/kubernetes/kubernetes/pull/104915), [@alculquicondor](https://github.com/alculquicondor))...

### EndpointSlices are now enabled by default

EndpointSlices are an exciting new API that provides a scalable and extensible alternative to the Endpoints API. EndpointSlices track IP addresses, ports, readiness, and topology information for Pods backing a Service.

- Added feature gate `MutatingAdmissionPolicy` for enabling mutation policy in admission chain. ([#123425](https://github.com/kubernetes/kubernetes/pull/123425), [@cici37](https://github.com/cici37))
- Added kubelet metrics to track the memory manager allocation and pinning. ([#121778](https://github.com/kubernetes/kubernetes/pull/121778), [@Tal-or](https://github.com/Tal-or))

## API Changes

- [CRI] Added a new field called `runtime_handler` into `PodSandbox` and `PodSandboxStatus` to track the `RuntimeClass` information of a pod. ([#73833](https://github.com/kubernetes/kubernetes/pull/73833), [@haiyanmeng](https://github.com/haiyanmeng))

## Detailed Bug Fixes And Changes

### API Machinery

- Added `kubernetes_feature_enabled` metric series to track whether each active feature gate is enabled. ([#112690](https://github.com/kubernetes/kubernetes/pull/112690), [@logicalhan](https://github.com/logicalhan))

- Registered metric `apiserver_request_body_size_bytes` to track the size distribution of requests by `resource` and `verb`. ([#120474](https://github.com/kubernetes/kubernetes/pull/120474), [@YaoC](https://github.com/YaoC)) [SIG API Machinery and Instrumentation]