all repos which are released (whichever way) need release branches.
and vice versa.
also, it needs to be the *right* release branch.

Task-number: QTBUG-50695
Change-Id: Id7b5d106d2d9bdf70e9d5276e205a3c7ea827144
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@theqtcompany.com>
Reviewed-by: Robert Loehning <robert.loehning@theqtcompany.com>
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>