Automatic merge from submit-queue (batch tested with PRs 50255, 50885)

remove dead code for cloner

I found some dead code in audit webhook backend.
This change do some clean work for: https://github.com/kubernetes/kubernetes/pull/48544/commits/2bbe72d4e09f7c95e1ad851187d4733a54644fbe

**Release note**:
```
NONE
```