Automatic merge from submit-queue (batch tested with PRs 46458, 50934, 50766, 50970, 47698)

Skip non-update endpoint updates

**What this PR does / why we need it**:

On large clusters, a large percentage of endpoint updates are actually non-updates that occur as a result of a change in an associated pod. This results in endpoint updates where the only field that has changed is the `TargetRef.ResourceVersion` in the endpoint address associated with the changed pod. Given enough of these non-updates, the endpoint controller's queue rate limit can be overwhelmed and legitimate updates can be delayed, resulting in (temporarily) broken services. We have clusters where we've seen endpoint updates take 9 minutes.

**Which issue this PR fixes** : fixes #50936 

**Special notes for your reviewer**:
N/A

**Release note**:
```release-note
Prevent unneeded endpoint updates
```