In addition to the previous good advice you could decide to accommodate the opposite: leave old modules for your scripts and only for them. You can do this pretty easily with Carton. You'd create a cpanfile for the scripts specifying the versions you want to freeze and then run things with carton. I don't have much experience with the package but the author is known for hits.

A full test suite is the real answer when you have the time or want something to last. Freezing at known working versions is a fine way to handle especially legacy code but it freezes out bug fixes and improvements as well as accidental breakage.