Type relations for function-like callables are too strict #1342
Description
Assignability, subtyping, and maybe also equivalence are currently too strict for function-like callables. For example, it should be possible to assign Mock() to a function-like callable, but we currently get:
from dataclasses import dataclass
from unittest.mock import Mock
@dataclass(order=True)
class Data:
value: int
def test_t():
d = Data(1)
# error: Object of type `Mock` is not assignable to
# attribute `__lt__` of type `(self: Data, other: Data) -> bool`
d.__lt__ = Mock()