Automatic merge from submit-queue
Removes alpha feature gate for affinity annotations.
**What this PR does / why we need it**:
In 1.5 we added a backstop to support alpha affinity annotations. This PR removes that support in favor of the Beta fields per discussions.
It also serves as a precursor to some of the component config work that @ncdc has done around @mikedanese design proposal.
xref: https://github.com/kubernetes/kubernetes/pull/41617
**Special notes for your reviewer**:
**Release note**:
```
Removes alpha feature gate for pod affinity annotations.
```
/cc @kubernetes/sig-scheduling-pr-reviews @kubernetes/sig-cluster-lifecycle-misc
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