Pyright fails to resolve `type(None)` to the `None` singleton, preventing standard type narrowing

### Describe the bug When `type(None)` is assigned to a variable and used in a `Union` type hint, Pyright fails to resolve it to the `None` singleton. This prevents standard type narrowing (e.g., `if not obj.my_list`) from removing the `None` branch, causing elements to be inferred as `Unknown`. ### Code Sample ```python import typing none_type = type(None) # Alias for the None singleton class MyClass: # Pyright treats this Union as list[str] | Unknown my_list: typing.Union[list[str], none_type] def fn(o: MyClass): if not o.my_list: return # Expected: list[str] # Actual: list[str | Unknown] elements = [e for e in o.my_list] ``` ### Environment Python 3.13, Pyright/Pylance v2026.2.1