provide type returns `Unknown` for type aliases

### Describe the Bug

```py
from typing import TypeAlias

A: TypeAlias = int | str

def f() -> A: ...

f # def mod.f() -> Unknown
```

hover / inlay hint works correctly, but provide type doesn't

@yangdanny97 i've tried to investigate why, but i can't figure it out :(

### Sandbox Link

_No response_

### (Only applicable for extension issues) IDE Information

_No response_