Don't allow building with old ytmusicapi versions

Apparently nobody looks at requirements.txt, so make this fail more
obviously.

As for why this is needed, ytmusicapi doesn't have a stable API, and
that means every time we adapt to a new version, old versions can break.
Having python backtraces thrown into the user's face would be a bad user
experience, so try to make sure packagers don't forget to update it.