Special dunder attributes on dataclass not treated as `__init__` args

Bug Report

Dunder-variables on dataclasses are considered to be arguments instead of ignored, per the dataclass documentation.

To Reproduce

https://mypy-play.net/?gist=27221945829d19cc0407d970cc1cb1f8

from dataclasses import dataclass

@dataclass
class Example:
    a: int
    
    __name__: str
    
    
e = Example(1)  # error: Missing positional argument "__name__" in call to "Example"  [call-arg]

Python run time does not consider __name__ as a required arguments, but mypy does.

Start with the linked mypy-play reproducer and trace the dataclass handling responsible for constructing the Example call signature. Confirm the runtime behavior described in the issue, then verify that name is excluded from required init arguments and the Example(1) call no longer reports a missing argument.