Also if you get "smart" and donate on multiple cards, I would think it is a trivial task for github to determine is is a scam. The CC address would match you Address for the funds your receive.
Probably way too much work for this :)
> https://docs.github.com/en/sponsors/sponsoring-open-source-c...
> GitHub Sponsors does not charge any fees for sponsorships from personal accounts, so 100% of these sponsorships go to the sponsored developer or organization. The 10% fee for sponsorships from organizations is waived during the beta. For more information, see "About billing for GitHub Sponsors."