Automatic merge from submit-queue (batch tested with PRs 38990, 45781, 46225, 44899, 43663)

Support parallel scaling on StatefulSets

Fixes #41255

```release-note
StatefulSets now include an alpha scaling feature accessible by setting the `spec.podManagementPolicy` field to `Parallel`.  The controller will not wait for pods to be ready before adding the other pods, and will replace deleted pods as needed.  Since parallel scaling creates pods out of order, you cannot depend on predictable membership changes within your set.
```