False positive "return-value" from class method when using class generics #20301

Bug Report
Consider the following code:

# test.py
class MyClass[T: int | str]:
    def __init__(self, factory: type[T]) -> None:
        self.factory = factory

    def func(self) -> T:
        return self.factory()

Running mypy test.py gives:

test.py:7:16: error: Incompatible return value type (got "int | str", expected "T")  [return-value]
Found 1 error in 1 file (checked 1 source file)

The type of self.factory is type[T] so self.factory() should be just T.

Am I missing something or is this a bug?

Your Environment

• Mypy version used: 1.18.2
• Mypy command-line flags: None
• Mypy configuration options from mypy.ini (and other config files): None
• Python version used: 3.13