Side gigs don't really earn much. If you've got a friend that you've worked with before and they have a startup or something, ask for some peanuts amount of equity as an hands on advisor. It'll do more for your CV than 20 hour side gigs glueing some libraries together.
Or pick a well known library / framework and contribute. Or rescue a "looking for [co-]maintainer" library out there.
Or pick a well known library / framework and contribute. Or rescue a "looking for [co-]maintainer" library out there.