An issue/merge-requests only moves forward by a human putting effort in.
Wether the issue is open, closed, autoclosed or flagged with a "stale"
label doesn't matter in theory.
In practice, humans don't like getting their issues/merge-requests
autoclosed. Instead, add a "stale" label.
There was always a benefit of this automatic action. It tended to
generate some feedback and new action. Sometimes it even brought new
attention to the issue/merge-request to get it fixed. That is hopefully
also the case with the stale label.
This fixes the pipeline as 'gem' will be installed by default in the
container image.
Also fix wording and run gitlab-triage in debug mode to get more output.