* kubeadm: add a preflight check that throws a warning if the cgroup driver for Docker on Linux is not "systemd" as per the k8s.io CRI installation guide. ([#73837](https://github.com/kubernetes/kubernetes/pull/73837), [@neolit123](https://github.com/neolit123))

* Kubeadm no longer throws an error for the --cloud-provider=external flag. ([#58259](https://github.com/kubernetes/kubernetes/pull/58259), [@dims](https://github.com/dims))

- Added new `CRDValidationRatcheting` alpha feature. During a PATCH or UPDATE Validation Ratcheting discards errors thrown by unchanged portions of the resource from most OpenAPI schema validations. ([#118990](https://github.com/kubernetes/kubernetes/pull/118990), [@alexzielenski](https://github.com/alexzielenski))

- Kubeadm: the deprecated kube-dns is no longer supported as an option. If "ClusterConfiguration.dns.type" is set to "kube-dns" kubeadm will now throw an error. ([#99646](https://github.com/kubernetes/kubernetes/pull/99646), [@rajansandeep](https://github.com/rajansandeep)) [SIG Cluster Lifecycle]

## Other Notable Changes

### SIG API Machinery

- `kubectl get apiservice` now shows the target service and whether the service is available ([#67747](https://github.com/kubernetes/kubernetes/pull/67747), [@smarterclayton](https://github.com/smarterclayton))

ontainerd.sock`, Windows: `npipe:////./pipe/containerd-containerd`) instead of the one for Docker. If the `Init|JoinConfiguration.nodeRegistration.criSocket` field is empty during cluster creation and multiple sockets are found on the host always throw an error and ask the user to specify which one to use by setting the value in the field. Make sure you update any kubeadm configuration files on disk, to not include the dockershim socket unless you are still using kubelet version < 1.24 with kubeadm...

- Kubeadm: switched the validation check for Linux kernel version to throw warnings instead of errors. ([#131919](https://github.com/kubernetes/kubernetes/pull/131919), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle and Node]

- Added a new metric `apiserver_flowcontrol_request_concurrency_in_use` that shows the number of
  seats (concurrency) occupied by the currently executing requests in the API Priority and Fairness system. ([#102795](https://github.com/kubernetes/kubernetes/pull/102795), [@tkashem](https://github.com/tkashem))

- Kubeadm: added `show-join-command` as a new separate phase at the end of `kubeadm init`. You can skip printing the join information by using `kubeadm init --skip-phases=show-join-command`. Executing only this phase on demand will throw an error because the phase needs dependencies such as bootstrap tokens to be pre-populated. ([#111512](https://github.com/kubernetes/kubernetes/pull/111512), [@SataQiu](https://github.com/SataQiu))

- Kubeadm: do not throw errors if the current system time is outside of the NotBefore and NotAfter bounds of a loaded certificate. Print warnings instead. ([#94504](https://github.com/kubernetes/kubernetes/pull/94504), [@neolit123](https://github.com/neolit123)) [SIG Cluster...