Mypy incorrectly infers that parameters are positional-only for `__eq__` methods autogenerated with `@dataclass`

For a class decorated with @dataclass, mypy assumes that the class's __eq__ method will have the exact same signature as object.__eq__. However, this is subtly incorrect. Whereas the signature of object.__eq__ is def __eq__(self, other: object, /) -> bool: ..., the signature of MyDataclass.__eq__ is def __eq__(self, other: object) -> bool: .... I.e., for the method auto-generated by @dataclass, the second argument is positional-or-keyword; whereas the second argument is positional-only for object.__eq__.

Minimal repro (using mypy 0.931, Python 3.10 -- try it on mypy playground here):

from dataclasses import dataclass

@dataclass
class Foo: ...

reveal_type(Foo.__eq__)  # Revealed type is "def (builtins.object, builtins.object) -> builtins.bool"

Inizia con la riproduzione minima usando dataclass e verifica come mypy gestisce il metodo eq generato automaticamente rispetto a object.eq. Verifica la firma mostrata, quindi aggiungi una copertura che dimostri che il secondo parametro è positional-or-keyword per i metodi di uguaglianza di dataclass; il lavoro è completato quando scompare l’inferenza errata di positional-only.