Automatic merge from submit-queue (batch tested with PRs 45125, 45242)

Update labels.yaml with sig labels

**What this PR does / why we need it**: Updates labels.yaml to reflect the state of labels in this repo.  Consumed by https://github.com/kubernetes/test-infra/blob/master/mungegithub/mungers/check-labels.go to ensure these labels continue to exist.

**Release note**:
```release-note
NONE
```