gitlab CI: move MR check to a later stage
This gives the developer enough time to file an MR after pushing a branch. Having this run in the first stage means we get false positives because no MR has been filed yet when the job is run.
This gives the developer enough time to file an MR after pushing a branch. Having this run in the first stage means we get false positives because no MR has been filed yet when the job is run.