Type hint parsing with ParamSpec complains about that ParamSpec has no attribute '__origin__'

[wldhg]

Describe the bug

below error occurs while buliding documentation

WARNING: error while formatting arguments for example.ex1.ExampleClass: 'typing.ParamSpec' object has no attribute '__origin__'
WARNING: error while formatting signature for example.ex1.ExampleClass: Handler <function record_typehints at 0x7f8baa513c40> for event 'autodoc-process-signature' threw an exception (exception: 'typing.ParamSpec' object has no attribute '__origin__')

How to Reproduce

I prepared a minimal example for this.

https://github.com/wldhg/sphinx-paramspec

conf.py

project = "Example"
copyright = "example"
author = "example"

extensions = [
    "sphinx.ext.autodoc"
]

index.rst

.. automodule:: example.ex1
  :members:

ex1.py

class ExampleClass[**P]:
    """
    example class
    """
    def __init__(self, *args: P.args, **kwargs: P.kwargs):
        ...


def example_function[**P](cls: type[ExampleClass[P]]) -> type[ExampleClass[P]]:
    """
    example function
    """
    return cls

Environment Information

- Python 3.12.2 on Linux x86-64 machine
- sphinx 7.2.6

Sphinx extensions

[
    "sphinx.ext.autodoc"
]

Additional context

No response

[wldhg]

Also the error seems to occur in here:

sphinx/sphinx/util/typing.py

Lines 358 to 365 in 5523c9b

	if _name:
	qualname = _name
	elif annotation_qualname:
	qualname = annotation_qualname
	else:
	qualname = stringify_annotation(
	annotation.__origin__, 'fully-qualified-except-typing',
	).replace('typing.', '') # ex. Union