bug: merge_init_into_class does not merge overloads

[kaktus42]

Description of the bug

When using merge_init_into_class, signature overloads (typing.overload) are not merged into the class' docs.

To Reproduce

Example:

from typing import overload

class Foo:
    """
    Foo class docs
    """

    @overload
    def __init__(self, *, a: str): ...

    @overload
    def __init__(self, *, b: str): ...

    def __init__(self, **kwargs):
        """
        Foo constructor docs
        """
        pass

merge_init_into_class: true	merge_init_into_class: false

WRITE MRE / INSTRUCTIONS HERE

Expected behavior

The overload defs should also be rendered.

Environment information

griffe --debug-info  # | xclip -selection clipboard

• System: macOS-14.7.1-x86_64-i386-64bit
• Python: cpython 3.12.7 (/usr/local/Caskroom/miniconda/base/envs/medconb-client/bin/python3.12)
• Environment variables:
• Installed packages:
  • griffe v1.5.1

Additional context