Maybe just hide them if they post GitHub links.
I've loved some of the vibe coded apps that are hosted somewhere that have made the front page, but a lot of the links to GitHub projects intended to farm stars for throwaway portfolio padding (which often don't work).
Egh. No silver bullet here.
As someone who has posted a couple of Show HNs that went to GitHub, I'd have to respectfully disagree. :) We are sharing language libraries, so GH makes the most sense. You can get the library and sample apps there.