Re-enable fuzzing for relaxed atomics (#8930)

Part of #8904. Reverts #8909. V8 updated according to
https://github.com/WebAssembly/relaxed-atomics/issues/3
[link](https://chromium-review.googlesource.com/c/v8/v8/+/8110620), so
Binaryen and V8 have the same bit interpretation again.