Handling failed pipelines in MR with multiple commits

This happened in e.g. !54 (merged)

If multiple commits are made the first commit can trigger a CI job which fails but in the 2nd commit the failed job might not be triggered (E.g. GRID file only added in first commit and not changed in second). In this case the overall pipeline status is green, which is not what we want.

See discussions in: https://gitlab.com/gitlab-org/gitlab-foss/issues/53530

Options that could be tried:

• Try only:merge_requests (although this also has problems, see https://gitlab.com/groups/gitlab-org/-/epics/957)
• Remove only:changes and launch all jobs for all commits possibly moving the git diff commands in gitlab-ci.yml so that if nothing is to be checked the job can exit before executing the time consuming scripts