Napoleon/Sphinx submodule to document interfaces fails with new version

[oesteban]

Caught at the last nireports build (https://readthedocs.org/projects/nireports/builds/27316489/):

Running Sphinx v8.2.1
loading translations [en]... done
WARNING: while setting up extension sphinxcontrib.apidoc: Failed to convert [[<class 'str'>]] to a frozenset


Versions
========

* Platform:         linux; (Linux-6.8.0-1021-aws-x86_64-with-glibc2.35)
* Python version:   3.11.10 (CPython)
* Sphinx version:   8.2.1
* Docutils version: 0.21.2
* Jinja2 version:   3.1.5
* Pygments version: 2.19.1

Last Messages
=============

None.

Loaded Extensions
=================

None.

Traceback
=========

    Traceback (most recent call last):
      File "/home/docs/checkouts/readthedocs.org/user_builds/nireports/envs/174/lib/python3.11/site-packages/sphinx/cmd/build.py", line 414, in build_main
        app = Sphinx(
              ^^^^^^^
      File "/home/docs/checkouts/readthedocs.org/user_builds/nireports/envs/174/lib/python3.11/site-packages/sphinx/application.py", line 291, in __init__
        self.setup_extension(extension)
      File "/home/docs/checkouts/readthedocs.org/user_builds/nireports/envs/174/lib/python3.11/site-packages/sphinx/application.py", line 489, in setup_extension
        self.registry.load_extension(self, extname)
      File "/home/docs/checkouts/readthedocs.org/user_builds/nireports/envs/174/lib/python3.11/site-packages/sphinx/registry.py", line 541, in load_extension
        mod = import_module(extname)
              ^^^^^^^^^^^^^^^^^^^^^^
      File "/home/docs/.asdf/installs/python/3.11.10/lib/python3.11/importlib/__init__.py", line 126, in import_module
        return _bootstrap._gcd_import(name[level:], package, level)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "<frozen importlib._bootstrap>", line 1204, in _gcd_import
      File "<frozen importlib._bootstrap>", line 1176, in _find_and_load
      File "<frozen importlib._bootstrap>", line 1147, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
      File "<frozen importlib._bootstrap_external>", line 940, in exec_module
      File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
      File "/home/docs/checkouts/readthedocs.org/user_builds/nireports/envs/174/lib/python3.11/site-packages/nipype/sphinxext/apidoc/__init__.py", line 16, in <module>
        class Config(NapoleonConfig):
      File "/home/docs/checkouts/readthedocs.org/user_builds/nireports/envs/174/lib/python3.11/site-packages/nipype/sphinxext/apidoc/__init__.py", line 42, in Config
        _config_values = {
                         ^
    TypeError: 'tuple' object is not a mapping


The full traceback has been saved in:
/tmp/sphinx-err-dqo8vqaa.log

To report this error to the developers, please open an issue at <https://github.com/sphinx-doc/sphinx/issues/>. Thanks!
Please also report this if it was a user error, so that a better error message can be provided next time.