support `type[...]` where `...` is a generic alias

https://play.ty.dev/1ac81fdc-057b-487a-9910-1d690b4ca673

```py
class C[T]:
    pass

class D[T]:
    pass

var: type[C[int]] = D[int]

```

This assignment should be an error, but currently isn't.