`Top[]` and `Bottom[]` should respect upper bounds and constraints

Minimal reproducible example ([playground](https://play.ty.dev/64e41ddb-8baf-43e0-abfd-64c45f0004c5)):

```python
class Covariant[T: int]:
    def _(self) -> T: ...

def _(covariant: Top[Covariant[Any]]):
    reveal_type(covariant)  # `Covariant[object]`, but should instead be `Covariant[int]`
```
