Unused import not detected F401

```python
import mylib.mylib as cli
import mylib.test

cli.test()
```

Expected error:

```
test2.py:2:8: F401 [*] `mylib.test` imported but unused
```

Actual: 

```
> ruff check --select F .\test2.py
All checks passed!
> ruff --version
ruff 0.8.3
```

