Backport CPython PR 105976

[AlexWaygood]

Backport of python/cpython#105976

[JelleZijlstra]

Thanks! There's a test failure on 3.12.

Also, let's land this after 4.7.0 final goes out next week?

[AlexWaygood]

Also, let's land this after 4.7.0 final goes out next week?

It fixes a regression introduced in the 4.6 series... But I'm happy to defer to your judgement as RM :)

I do appear to have been the only user of typing_extensions.Protocol affected by the regression I introduced 😆

[JelleZijlstra]

Ah you're right, we should fix this in 4.7.0 then.