Make `.stage_done` available also on docs MRs
What does this MR do?
Make the .stage_done
helper job available also on docs
MRs.
Why was this MR needed?
See #26593 (closed)
What's the best way to test this MR?
Create a docs
-only MR based on this branch and see if it doesn't generate an invalid yaml message.
What are the relevant issue numbers?
Closes #26593 (closed)