Reviewer Roulette - default to previous roulette if no timezone reviewer/maintainer found
Description
With !34862 (merged) Reviewer Roulette was changed to use timezone for determining the individuals for Review of Maintainer Review on GitLab MRs.
There are times where no reviewer/maintainer is found by timezone and none is added. In situations where no timezone reviewer/maintainer is found then the previous logic for selecting a reviewer/maintainer should be used.