At small scale of individual cases it's useless. It can block a large network with known characteristics. It's not going to block openclaw driving your personal browser with your login info.
> Would publishing a "human only" contribution license/code of conduct
It would get super muddy with edge cases. What about dependabot? What about someone sending you an automated warning about something important? There's nothing here that is bot specific either - a basic rule for "posting rants rather than useful content will get you banned" would be appropriate for both humans and bots.
We don't really need special statement here.
but the OSS use case described here is a pretty different case, what OP suggested may still be useful there
But it would be nice if Github had a feature that would let a human attest to a commit/PR, in a way that couldn't be automated. Like signed commits combined with a captcha or biometric or something (which I realize has its own problems but I can't think of a better way to do this attestation).
Then an Open Source maintainer could just automatically block unattested PRs if they want. And if someone's AI is running rampant at least you could block the person.