Return git clone step for ruby-build to ensureRubyEnv function

  - Returning this step which was removed prviously, because we need
    to override old ruby-build package installed on Jenkins slaves
  - Remove unused variable and unnecesary rm step

Fixes: PROD-29321

Change-Id: I0a84449bc3bcd03ef2a94bd648030b4b212d370e
1 file changed