Remove historic minergate trigger

What does this MR do?

This change includes a migration which is only relevant for GitLab.com (and staging).

For historic reasons and years ago, we have installed a trigger on ci_builds presumably to deal with mining activity. See https://gitlab.com/gitlab-org/gitlab/-/issues/322110 for the definition.

The trigger is only based on information from ci_builds.commands. Given certain values there, a function make_build_to_be_stuck_with_lock_version() gets triggered. However, ci_builds.commands has been retired and ignored for a while and is going to be removed soon (!54564 (comment 514501260)). Hence the conclusion that this mechanic has stopped to work in any case and should be removed.

We also drop the make_build_to_be_stuck() function as this seems to be closely related.

Availability and Testing

I wouldn't pass the Chesterton's Fence Test as I don't know the background of why we have this in the first place sure enough. I do know though that this hasn't changed since 3 years and it's practically broken anyways.

The assumption is that nothing else uses any of the make_build_to_be_*() functions. As a backup, find the function definitions along with the trigger in https://gitlab.com/gitlab-org/gitlab/-/issues/322110#note_515071667.