__new__ on abstract classes produces false positive "Cannot instantiate abstract class"

Bug Report

When an abstract class defines __new__ (note, not __init__) method, mypy produces error when that class is instantiated, even though __new__() does not imply instantiation.

To Reproduce

from abc import ABCMeta, abstractmethod


class Abstract(metaclass=ABCMeta):
    def __new__(cls) -> "Abstract":
        return super().__new__(Concrete)

    @abstractmethod
    def hello(self) -> int:
        ...


class Concrete(Abstract):
    def hello(self) -> int:
        return 0


x = Abstract()
print(x.hello())

Expected Behavior

No errors reported when checked with mypy. Calling a class with __new__ method shuld be effectively treated as just calling a simple method, like

def make_abstract() -> "Abstract":
    return Concrete()

Actual Behavior

error message is printed:

 error: Cannot instantiate abstract class "Abstract" with abstract attribute "hello"  [abstract]

Your Environment

• Mypy version used: mypy-0.991
• Mypy command-line flags: none
• Mypy configuration options from mypy.ini (and other config files): none
• Python version used: 3.10.6

Nell’issue non sono indicati file del repository né test. Inizia dal riproduttore Python fornito e segui il controllo di mypy dell’istanziazione di classi astratte quando è definito new; il lavoro è completato quando il falso errore [abstract] non è più presente e la diagnosi prevista per le classi astratte continua a essere coperta da un test di regressione.