Spec and conformance tests disagree on converting constructors into callable for classes with `__new__` and `__init__`

For classes with both __new__ and __init__, when converting the constructor into a Callable, the spec says that

https://github.com/python/typing/blame/20096eeba502b1bf955fcf62b389adbaa63fc61b/docs/spec/constructors.rst#L457

    class B:
        """ __new__ and __init__ """
        def __new__(cls, *args, **kwargs) -> Self:
            ...

        def __init__(self, x: int) -> None:
            ...

    reveal_type(accepts_callable(B))  # ``def (*args, **kwargs) -> B | def (x: int) -> B``

The conformance test says that

https://github.com/python/typing/blob/20096eeba502b1bf955fcf62b389adbaa63fc61b/conformance/tests/constructors_callable.py#L54-L64

将 docs/spec/constructors.rst 中链接部分附近描述的构造函数行为与 conformance/tests/constructors_callable.py 中的情况进行比较。确定对于同时定义 new 和 init 的类，预期使用哪种 callable 类型，然后使规范与一致性测试保持一致，并运行相关的构造函数一致性检查。