* Switch JSON marshal/unmarshal to json-iterator library.  Performance should be close to previous with no generated code. ([#48287](https://github.com/kubernetes/kubernetes/pull/48287), [@thockin](https://github.com/thockin))

- Kubelet don't forcefully close active connections on heartbeat failures, using the http2 health check mechanism to detect broken connections. Users can force the previous behavior of the kubelet by setting the environment variable DISABLE_HTTP2. ([#108107](https://github.com/ku...

- Fix kubelet to not leak goroutines/intofiy watchers on an inactive connection if it's closed ([#67285](https://github.com/kubernetes/kubernetes/pull/67285), [@yujuhong](https://github.com/yujuhong))
- Fix pod launch by kubelet when --cgroups-per-qos=false and --cgroup-driver="systemd" ([#66617](https://github.com/kubernetes/kubernetes/pull/66617), [@pravisankar](https://github.com/pravisankar))

- The Kubernetes API server now correctly detects and closes existing TLS connections when its client certificate file for kubelet authentication has been rotated. ([#115567](https://github.com/kubernetes/kubernetes/pull/115567), [@enj](https://github.com/enj)) [SIG API Machinery, Node and Testing]

package org.junit.internal; public synchronized class ArrayComparisonFailu extends AssertionError { private static final long serialVersionUID = 1; private final java.util.List fIndices; private final String fMessage; private final AssertionError fCause; public void ArrayComparisonFailu(String, AssertionError, int); public void addDimension(int); public synchronized Throwable getCause(); public String getMessage(); public String toString(); } org/junit/internal/runners/MethodRoadie$1$1.class package...

### API Machinery

- kube-apiserver: the `--runtime-config` flag now supports an `api/beta=false` value which disables all built-in REST API versions matching `v[0-9]+beta[0-9]+`. ([#84304](https://github.com/kubernetes/kubernetes/pull/84304), [@liggitt](https://github.com/liggitt))

* Verify invalid secret/configmap/projected volumes before calling setup ([#68691](https://github.com/kubernetes/kubernetes/pull/68691), [@gnufied](https://github.com/gnufied))
* Immediately close the other side of the connection when proxying. ([#67288](https://github.com/kubernetes/kubernetes/pull/67288), [@MHBauer](https://github.com/MHBauer))

- [`KT-53460`](https://youtrack.jetbrains.com/issue/KT-53460) False positive smartcast warning in if block after if block
- [`KT-40851`](https://youtrack.jetbrains.com/issue/KT-40851) False MUST_BE_INITIALIZED_OR_BE_ABSTRACT error for a property which is initialised in the init block
- [`KT-59695`](https://youtrack.jetbrains.com/issue/KT-59695) K2: false negative NON_PUBLIC_CALL_FROM_PUBLIC_INLINE

- Do not unmount and mount subpath bind mounts during container creation unless bind mount changes ([#105512](https://github.com/kubernetes/kubernetes/pull/105512), [@gnufied](https://github.com/gnufied)) [SIG Storage]
- Don't prematurely close reflectors in case of slow initialization in watch based manager to fix issues with inability to properly mount secrets/configmaps. ([#104604](https://github.com/kubernetes/kubernetes/pull/104604), [@wojtek-t](https://github.com/wojtek-t))

- Fixes regression in logging spurious stack traces when proxied connections are closed by the backend ([#82588](https://github.com/kubernetes/kubernetes/pull/82588), [@liggitt](https://github.com/liggitt))