Allow certain users/roles to merge an MR with a failed pipeline even if "Pipelines must succeed" is enabled

Proposal

When "Pipelines must succeed" is enabled, certain users or roles should be able to "force merge" it regardless of pipeline status.

For certain users this would only serve as a shortcut: They can already modify the project settings to disable the setting, quickly merge the MR and then re-enable the setting. This is tedious and has some risk of allowing other people to do so as well while the setting is briefly changed.

There's also an argument to be made that being "Allowed to push and merge" to the target branch could also skip the pipelines by merging locally and then pushing to the target branch, so allowing them to bypass this setting also wouldn't add new ways to introduce undesired code changes.