Runloop compatible `waitFor` type

Is it feasible to provide a type for `waitFor` that is compatible with Ember's runloop functions?

Looking to do something like:
```ts
schedule('afterRender', waitFor(async () => { … }))
```

However this currently throws a type error:
```
Argument of type 'Function' is not assignable to parameter of type 'AnyFn'.
Type 'Function' provides no match for the signature '(...args: any[]): unknown'. ts(2345)
```

Adding this function override appears to minimally be enough to clear up the issue:
```ts
export default function waitFor(fn: AsyncFunction, label?: string): (...args: any[]) => unknown;
```

A possibly more robust solution:
```ts
export default function waitFor(fn: AsyncFunction, label?: string): (...args: unknown[]) => unknown;
```