Mixed domain testsuite should remove unneeded expanded dists as it goes

OldVersionCopier unzips the legacy AS zip for the version requested. But there is no subsequent cleanup.

Simplest is to have the method that unzips check for all the other versions besides the one being tested and remove any it finds. The tests execute grouped by version so when work on a new version begins the expanded dist for the previous version is not needed.

That will leave one behind, but that's ok. The problem here is the overall disk utilization during CI jobs and getting this down to just one is ok. And after the last version runs, the CI jobs complete anyway.