Formula installer req satisfied

Fixes #31471 and #30901.

Problem with pyqt5 was because we already had scheduled ```#<Dependency: "python3" [:recommended]>``` and ```sip``` was providing us with ```#<Python3Dependency: "python3" [:optional]>```.

I don't know if this is a correct fix for this, but it works in both cases.
Done. Yes, I think there is room for improvement. But I need to dive into the internals to understand how everything works.