Changes

feature(scripts/ops): add script `cherry_pick_pull.sh` (#2579)

This script is used to create a cherry pick pull request.

Usage:

```bash
./scripts/ops/cherry_pick_pull.sh upstream/release-7.5 98765
```

Thanks:
-
https://github.com/kubernetes/community/blob/master/contributors/devel/sig-release/cherry-picks.md
-
https://github.com/kubernetes/kubernetes/blob/master/hack/cherry_pick_pull.sh
 (commit: 4bda942)