false `bad-return` for a generator function with `Iterator[X] | T` return annotation

from collections.abc import Iterator


def gen(x: int) -> Iterator[int] | int:
    yield from range(4)
    return 5

ERROR sandbox.py:6:12-13: Returned type `Literal[5]` is not assignable to declared return type `None` [[bad-return](https://pyrefly.org/en/docs/error-kinds/#bad-return)]