Recipes do not get rebuilt when patches are updated

If you make a fix to a recipe that only changes a patch that is applied by the recipe, the recipe state is not invalidated since only the recipe mtime is used to determine that. You have to manually do buildone.

This has been known for a while, but it's important that we get this fixed because it's bad for the CI, and also for people running Cerbero.

CCing @ndufresne since it's relevant for CI.