Move open PRs to next milestone on release

[boesing]

Feature Request

Q	A
New Feature	yes
BC Break	no

Summary

In #90, a feature was requested to move issues from old milestones to new one.
I've recently manually moved open PRs in https://github.com/laminas/laminas-ci-matrix-action/pulls to the latest minor. One of these had a bump of 5 minor releases.

I wonder if it is possible to automatically re-target open PRs to the next milestone (major or minor) rather than keeping them untouched.