- Updated the Partitionable Devices feature to support referencing counter sets across ResourceSlices within the same resource pool. Devices from incomplete pools were no longer considered for allocation. This change introduced backwards-incompatible updates to the alpha feature, requiring any ResourceSlices using it to be removed before upgrading or downgrading between v1.34 and v1.35. ([#134189](https://github.com/kubernetes/kubernetes/pull/134189), [@mortent](https://github.com/mortent))...

Interface (CRI) version has increased from v1alpha1 to v1alpha2. Runtimes implementing the CRI will need to update to the new version, which configures container namespaces using an enumeration rather than booleans. This change to the alpha API is not backwards compatible; implementations of the CRI such as containerd, will need to update to the new API version. ([#58973](https://github.com/kubernetes/kubernetes/pull/58973), [@verb](https://github.com/verb))

* The default Flexvolume plugin...

  https://github.com/kubernetes-sigs/kustomize/releases/tag/kustomize%2Fv5.0.0 and https://github.com/kubernetes-sigs/kustomize/releases/tag/kustomize%2Fv5.0.1. 
  
  This is a new major release of kustomize, so there are a few backwards-incompatible changes, most of which are rare use cases, bug fixes with side effects, or things that have been deprecated for multiple releases already:
  

- Changes to timeout parameter handling in 1.20.0-beta.2 have been reverted to avoid breaking backwards compatibility with existing clients. ([#96727](https://github.com/kubernetes/kubernetes/pull/96727), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Testing]

    *   reflector_list_duration_seconds
    *   reflector_lists_total
    *   reflector_short_watches_total
    *   reflector_watch_duration_seconds
    *   reflector_watches_total
    * While this is a backwards-incompatible change, it would have been impossible to setup reliable monitoring around these metrics since the labels were not stable. 

* The kube-discovery Deployment isn't used anymore when creating a kubeadm cluster and shouldn't be used anywhere else either due to its insecure nature.
* The Certificates API has graduated from alpha to beta. This is a backwards-incompatible change since the alpha support is dropped, and therefore kubeadm v1.5 and v1.6 don't work together (for example kubeadm v1.5 can't join a kubeadm v1.6 cluster).
* Supporting only etcd3, with 3.0.14 as the minimum version.

    *   reflector_list_duration_seconds
    *   reflector_lists_total
    *   reflector_short_watches_total
    *   reflector_watch_duration_seconds
    *   reflector_watches_total
    * While this is a backwards-incompatible change, it would have been impossible to setup reliable monitoring around these metrics since the labels were not stable. 

- Drop additional rule requirement (cronjobs/finalizers) in the roles who use kubectl create cronjobs to be backwards compatible ([#124883](https://github.com/kubernetes/kubernetes/pull/124883), [@ardaguclu](https://github.com/ardaguclu)) [SIG CLI]
- Fix a bug that Pods could stuck in the unschedulable pod pool 

* fix: make azure disk URI as case insensitive ([#79020](https://github.com/kubernetes/kubernetes/pull/79020), [@andyzhangx](https://github.com/andyzhangx))

- Drop additional rule requirement (cronjobs/finalizers) in the roles who use kubectl create cronjobs to be backwards compatible ([#124883](https://github.com/kubernetes/kubernetes/pull/124883), [@ardaguclu](https://github.com/ardaguclu)) [SIG CLI]