In bug 1627996 we've added a conditional check in bouncerscript to skip
bouncer_aliases_check for Nazgul jobs, since the latter has no public interface. Once we've done with the switch, we should instead remove that code (basically revert parts of https://github.com/mozilla-releng/scriptworker-scripts/pull/201 ) and rely on the fact that Nazgul will become the new bouncer.
Along those lines, other changes include but are not limited to:
- removing all 'nazgul' related jobs from in-tree
- pointing the docker configs in bouncer for the current bouncer to Nazgul
This way we can transition nicely to the new bouncer interface.