For the same reason we do in the rpm-ostree tests. This also
made sure the test run worked when I was offline on a plane.
Closes: #1583
Approved by: jlebon
OK so I noticed that something was failing and we were missing
`set -xeuo pipefail` in our shells. That of course revealed
the ansible tests didn't actually work - my only defense
here is spending so much time fighting to get it through CI
and trying something new.
Anyways, to make the staged-deploy tests work we need a task
that actually uses `rpm-ostree override` rather than `usroverlay`.
Let's make this a bit saner and have a clean split between
tests that are "shell-script+usroverlay" and "ansible+override".
Closes: #1577
Approved by: jlebon
Colin Walters