remove check for branch name conforming to porting conventions

As discussed in tech call today: remove the check for branch naming conforming to porting conventions. this will have the effect that for every MR, it will check for a same-name branch in float and it will set that as its float reference. If there is none, the pre-validate job will turn yellow as a warning.

This will allow our rtpdump MR to be merged and also change the behaviour for all future MRs.

@pihlajakuja, or @norvell, I would appreciate a short review of the logic in the scripts.