[Bug]: numbers.Number causes type warning

[EarlMilktea]

Describe the bug

numbers.Number and similar ABCs in numbers are causing mypy warnings.

To Reproduce

from numbers import Number


def f(x: Number) -> Number:
    # ERROR: Operator "*" not supported for types "Literal[3]" and "Number"
    return 3 * x

Additional context

We cannot build type-stable interfaces with numbers.Number, as clearly stated in Fluent Python, 2nd ed:

Sadly, the numeric tower was not designed for static type checking. The root ABC—
numbers.Number—has no methods, so if you declare x: Number, Mypy will not let
you do arithmetic or call any methods on x.