A long time ago, We added the image prepulling as a workaround due to
the overwhelming amount of flake caused by pulling during the tests.
This functionality has been broken for a while now when we switched to a
COS image where mounting `docker` binary into `busybox` stopped working.
So we just have dead code we should clean up.
Change-Id: I538171a5c1d9361eee7f9e0a99655b88b1721e3e
Automatic merge from submit-queue (batch tested with PRs 62208, 62114, 62144, 60460, 62214). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
removes job scaler, continued
Builds on https://github.com/kubernetes/kubernetes/pull/61912 (original commit is there for credit/blame)
This keeps all the updates to the scaler building and all the test and reaper cleanup. It just keeps a fake job scaler around for a different command path and the reaper.
/assign @p0lyn0mial
/assign @soltysh
```release-note
NONE
```
note that we don't change the behaviour of kubectl.
For example it won't scale new resources. That's the end goal.
The first step is to retrofit existing code to use the generic scaler.
