I've considered DoSing myself a few times, but then change my mind and just publish the release :)

A PR to change it to "(\d+\.\d+\.\d+)([a-zA-Z]+\d+)?$" would be fine, but is not urgent. It certainly doesn't need to be backported, as this is only ever used from master these days.

Personally I'd be just as happy closing the issue. I know that the current script works, and there's nothing worse than breaking a release because someone has changed the release scripts without testing them properly.