test: add callback return type tests for mutation callbacks (#9252)

* Revert "refactor(types): narrow onSuccess/onError/onMutate/onSettled callback types to Promise<void> | void (#9202)"

This reverts commit 982f6ca6073c68a152621772e3cd42c02150917f.

* test: add callback return type tests for mutation callbacks

Adds test coverage for mutation callback return types, inspired by the discussions and [TkDodo's comment](https://github.com/TanStack/query/pull/9245#issuecomment-2939664588
) in #9245 and the original Promise.all() edge case identified in #9202.

The original PR #9202 narrowed callback return types from `Promise<unknown> | unknown`
to `Promise<void> | void`, but this broke common patterns like:

```ts
onSuccess: (data) => Promise.all([
  invalidateQueries(),
  trackAnalytics(),
])
```

As noted in [the original discussion](https://github.com/TanStack/query/pull/9202#issuecomment-2934491122),
this `Promise.all()` pattern was a legitimate use case that many users relied on.

These tests ensure we support all the callback patterns that users expect:

✅ **Sync patterns**: Implicit void, explicit void, non-void returns
✅ **Async patterns**: Async functions, Promise.resolve(), Promise<T> returns
✅ **Promise.all() patterns**: The original breaking case from #9202
✅ **Promise.allSettled() patterns**: Additional parallel operation support
✅ **Mixed patterns**: Different callback types in same mutation
✅ **Error handling**: All patterns work in error scenarios
✅ **Return value isolation**: Callback returns don't affect mutation result

* refactor(tests): remove unnecessary parameters in mutation tests

* test(mutations): fix mutation test ordering with error handling and cleanup verification

---------

Co-authored-by: Dominik Dorfmeister <office@dorfmeister.cc>