`Storage` cannot be subclassed with `mypy --disallow-any-expr`

[pomponchik]

With skelet==0.0.21 and mypy==1.14.1, merely subclassing Storage fails under strict Any checks.

Reproduction

Create example.py:

from skelet import Storage


class Config(Storage):
    pass

Run:

mypy --strict --disallow-any-expr example.py

Actual result:

example.py: error: Expression type contains "Any" (has type "type[Storage]")  [misc]

Expected result: a typed Storage subclass with no fields should type-check without suppressions.

reveal_type(Storage) shows the exposed constructor type includes AbstractSource[Any] and **kwargs: Any, so downstream libraries must currently disable misc merely to define configuration classes.