Stop running merged pipelines for drafts
What does this MR do and why?
In a previous MR (!86612 (merged)) we removed a mergeable_state
check when deciding whether to run a merged pipeline or not, however this meant that draft mr's are now running merged pipelines.
We should add the draft check back in so they are running detached, rather than merged.
Related issue: #247067 (comment 1015274730)
Edited by Marc Shaw