Auto bump pkgrel when some dependencies are upgraded

[petronny]

Eg. bump for python-blahblah when python has a major upgrade.

[Freso]

People using AUR packages should know to rebuild their local packages themselves when a new major Python (or Perl or Ruby or …) is released without package maintainers having to bump pkgrel’s. I get that your situation might be a bit different maintaining a separate repository for/of precompiled packages and it likely makes sense in that case, but please don’t enable this for packages being auto-updated by this that are not part of the arch4edu repository. Or at the very least allow to opt-out of it.