Bug: Tests hang when using async act() with "next" and "experimental" release channels

[bvaughn]

Repro case here:
https://github.com/bvaughn/react-createRoot-Suspense-async-act

npm install
npm run test

This is stripped down to the point of being a pretty silly test case. I was trying to report a more complicated bug, related to a Suspense cache invalidation, but noticed that I'm having difficulty getting even a more simple case to work with "next" and "experimental" release channels.

Maybe this has to do with changes related to new use semantics?

---

Note that with react/react-dom "latest" channel installed– the tests behave as I would expect. One fails with a warning about an update outside of act and the other passes. With either "next" or "experimental" channel though, the async act test case hangs forever.

cc @acdlite

[bvaughn]

Out of curiosity, I updated to the "experimental" channel and replaced the throw mechanism with use(promise) – and the async act test still hangs.

[bvaughn]

Fixed via #26317