PYI052 should ignore assignments in subclass of enum without enum members

[henribru]

PYI052 correctly accepts the following code:

from enum import Enum

class Baz(Enum):
    FOO = 0
    BAR = 1

However, it flags the assignments to FOO and BAR in this code:

from enum import Enum

class Foo(Enum):
    ...

class Bar(Foo):
    FOO = 0
    BAR = 1

Inheriting from enums without enum members works at runtime and is understood by typecheckers, so I think these two examples should be treated the same. https://mypy-play.net/?mypy=latest&python=3.11&gist=cdb6a82662cbb77416bb64692606cb83

Reproduced with v0.1.6 running ruff foo.pyi --select PYI052 without any settings in pyproject.toml.

[henribru]

Thanks for the prompt fix as always, you're awesome!