GH-99108: Fix Setup in addition to Setup.stdlib.in by msprotz · Pull Request #123146 · python/cpython

this looks correct to me -- or at least it matches the other ones. I could run a test build but that's going to take more time than I have free today :(

There is no way to get Modules/Setup "correct"; it never will be and it never has been. It should be removed, and the (few, hopefully) projects depending on it should find other ways to get what they need.