Automatic merge from submit-queue (batch tested with PRs 38154, 38502)
Rename "release_1_5" clientset to just "clientset"
We used to keep multiple releases in the main repo. Now that [client-go](https://github.com/kubernetes/client-go) does the versioning, there is no need to keep releases in the main repo. This PR renames the "release_1_5" clientset to just "clientset", clientset development will be done in this directory.
@kubernetes/sig-api-machinery @deads2k
```release-note
The main repository does not keep multiple releases of clientsets anymore. Please find previous releases at https://github.com/kubernetes/client-go
```
Automatic merge from submit-queue
Fix scheduler_perf test so that QPS is non-zero even if there is a scheduling "cold start"
@gmarek ... is something like this more realistic as an expectation ? That is, wait till scheduling starts, then wait 1 second before any polling attempts.... i.e.
- gaurantee uniform sleep before measure, by doing it first rather then last
- print the initial status so that its easier to debug in case of issues
#36532