Allow running GitLab QA for merged merge requests with a source branch removed
Description
Currently whenever someone clicks package-and-qa action in a merge request widget of a merged merge request, action is going to fail because of missing branch (source branch already removed).
It fails, because we are using GIT_DEPTH setting in the .gitlab-ci.yml, thus a branch is required to perform a clone.
Proposal
Consider not using GIT_DEPTH for package-and-qa job in merge requests, measure the impact on cloning time before making a decision about disabling it permanently for this job.
Edited by Martin Wortschack