The merge-output-to-logs role is not doing anything in this test. As
described inline, this merges files in
zuul.executor.work_root/<docs,artifacts> into the
zuul.executor.log_root directory so they are available in change
results.
Since this job doesn't publish anything there, this role is unused.
merge-output-to-logs currently can't run because it tries to run shell
scripts on the executor. Thus we can remove this unused role and
restore the job.
Change-Id: I1afc905aa8d9c420bed316e99760ad7ad1d838ce
6f43acde41