method `self` type appears to be unknown (Flag, Python 3.11)

In a method of a class derived from Flag, the type of self appears to be unknown.

To Reproduce

import enum

class Foo(enum.Flag):
    A = 1
    B = 2

    def names(self):
        return [v.name for v in list(self.__class__) if self & v]

Expected Behavior

no errors

Actual Behavior

$ mypy --check-untyped-defs flag.py
flag.py:8: error: "object" has no attribute "name"  [attr-defined]
flag.py:8: error: Unsupported operand types for & ("Foo" and "object")  [operator]

Though I can resolve the error by annotating self with typing_extensions.Self, I'm not sure that should be necessary.

Your Environment

• Mypy version used: 1.2.0
• Python version used: 3.11.0

Start with the flag.py reproducer and run it using mypy --check-untyped-defs to confirm the reported errors. Trace how mypy types list(self.__class__) and the Flag operations, then add a regression test showing that the method produces no errors without annotating self.