Automatic merge from submit-queue (batch tested with PRs 40812, 39903, 40525, 40729)
Add CI coverage for client-go and staging/copy.sh
Client-go master and `staging/copy.sh` keep breaking, leading to frustration of users outside of the inner refactoring circle. This PR adds minimal smoke testing for both.
**Note**: this enforces the split of PRs which change apimachinery and client-go in parallel (via some local "temporary commit" hacking).
- [x] @caesarxuchao ~~do we have to delete the example directory from the upstream repo?~~ merge https://github.com/kubernetes/test-infra/issues/1765