CHANGELOG for removing use of alpha initializers

Author: roycaihw

CHANGELOG.md

@@ -25,6 +25,7 @@
 - Introduce RuntimeClass to NodeV1alpha1Api and NodeV1beta1Api [kubernetes/kubernetes#74433](https://github.com/kubernetes/kubernetes/pull/74433)
 - Graduate PriorityClass API to GA SchedulingV1Api [kubernetes/kubernetes#73555](https://github.com/kubernetes/kubernetes/pull/73555)
 - Introduce CSINodeInfo and CSIDriver to StorageV1beta1Api [kubernetes/kubernetes#74283](https://github.com/kubernetes/kubernetes/pull/74283)
+- The alpha Initializers feature, `admissionregistration.k8s.io/v1alpha1` API version, `Initializers` admission plugin, and use of the `metadata.initializers` API field have been removed. Discontinue use of the alpha feature and delete any existing `InitializerConfiguration` API objects before upgrading. The `metadata.initializers` field will be removed in a future release. The parameter `include_uninitialized` has been removed. [kubernetes/kubernetes#72972](https://github.com/kubernetes/kubernetes/pull/72972)
 
 # v9.0.0
 **Bug Fix:**