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