> when people are pushing free software on you they are kind of in it for themselves

I strongly disagree with this. The free (as in both freedom and as in free beer) software movement was to provide an alternative to proprietary and closed-source software, which is developed by people and corporations who are openly in it for themselves.

> Like 10-100 bucks per PR to cover the cost of the extra vigilance. Also I could see migrations away from github, to AI free dependency hosting or something like that. Its an interesting challenge. But its not insurmountable.

You could just leave your project where it's at, keep it open source, and simply not accept outside contributions. Lots of open source software operates this way. The Ladybird browser notably switched to this model recently as a reaction to AI pull requests.