- If the user specifies an invalid timeout in the request URL, the request will be aborted with an HTTP 400.

* WATCHLIST calls are now reported as WATCH verbs in prometheus for the apiserver_request_* series.  A new "scope" label is added to all apiserver_request_* values that is either 'cluster', 'resource', or 'namespace' depending on which level the query is performed at. ([#52237](https://github.com/kubernetes/kubernetes/pull/52237), [@smarterclayton](https://github.com/smarterclayton))...

`meta.k8s.io/v1beta1` and configurations must be changed to use the new API.  Clients may request alternate representations of normal Kubernetes objects by passing an `Accept` header like `application/json;as=Table;g=meta.k8s.io;v=v1beta1` or `application/json;as=PartialObjectMetadata;g=meta.k8s.io;v1=v1beta1`.  Older servers will ignore this representation or return an error if it is not available.  Clients may request fallback to the normal object by adding a non-qualified mime-type to their `Accept`...

### Feature

- #### Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:
  
  <!--
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  When adding links which point to resources within git repositories, like
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- Deprecated prometheus request meta-metrics have been removed
 `http_request_duration_microseconds` `http_request_duration_microseconds_sum` `http_request_duration_microseconds_count`
 `http_request_size_bytes`
 `http_request_size_bytes_sum`
 `http_request_size_bytes_count`
 `http_requests_total, http_response_size_bytes`
 `http_response_size_bytes_sum`

#### Dynamic Admission Control

* Pod spec is mutable when the pod is uninitialized. The API server requires the pod spec to be valid even if it's uninitialized. Updating the status field of uninitialized pods is invalid.([#51733](https://github.com/kubernetes/kubernetes/pull/51733))

      - `kubeproxy_sync_proxy_rules_latency_microseconds` -> `kubeproxy_sync_proxy_rules_duration_seconds`
      - `apiserver_request_latencies` -> `apiserver_request_duration_seconds`
      - `apiserver_dropped_requests` -> `apiserver_dropped_requests_total`
      - `etcd_request_latencies_summary` -> `etcd_request_duration_seconds`
      - `apiserver_storage_transformation_latencies_microseconds ` -> `apiserver_storage_transformation_duration_seconds`

WebhookConfiguration` so that webhooks can explicitly register as having dry-run support. If a dry-run request is made on a resource that triggers a non dry-run supporting webhook, the request will be completely rejected, with "400: Bad Request". Additionally, a new field is being added to the `admission.k8s.io/v1beta1.AdmissionReview` API object, exposing to webhooks whether or not the request being reviewed is a dry-run. ([#66936](https://github.com/kubernetes/kubernetes/pull/66936), [@jennybu...

- Updated `etcd` version to `3.5.8`. ([#117335](https://github.com/kubernetes/kubernetes/pull/117335), [@kkkkun](https://github.com/kkkkun))
- Updated apiserver metric `request_filter_duration_seconds` to include a 10s, 15s and 30s bucket.
Updated apiserver metric `request_wait_duration_seconds` to include a 15s bucket. ([#118945](https://github.com/kubernetes/kubernetes/pull/118945), [@andrewsykim](https://github.com/andrewsykim))

authentication now supports requiring specific claims with `--oidc-required-claim=<claim>=<value>` Previously, there was no mechanism for a user to specify claims in the OIDC authentication process that were requid to be present in the ID Token with an expected value. This version now makes it possible to require claims support for the OIDC authentication. It allows users to pass in a `--oidc-required-claims` flag, and `key=value` pairs in the API config, which will ensure that the specified required claims...