KeyError in GriffeLoader.load_module if two or more dots in python file name

[MikhailPasechnik]

Describe the bug
If there is a file with name which contains more than one dot (for example gunicorn.conf.py)
GriffeLoader.load_module fails with KeyError here

https://github.com/mkdocstrings/griffe/blob/master/src/griffe/mixins.py#L82-L83

...
  File "../python3.10/site-packages/griffe/loader.py", line 407, in _load_submodule
    member_parent[subparts[-1]] = self._load_module(
  File "../python3.10/site-packages/griffe/mixins.py", line 85, in __setitem__
    self.members[parts[0]][parts[1:]] = value  # type: ignore[attr-defined]
KeyError: 'gunicorn'

To Reproduce
Steps to reproduce the behavior:

1. create module with this structure

test/
       __init__.py
       some.thing.py

2. Run command

python -c "import griffe.loader;griffe.loader.GriffeLoader().load_module('test')"

3. See error

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Users/m/.local/share/virtualenvs/griffe-bug-j_gvc5DW/lib/python3.10/site-packages/griffe/loader.py", line 149, in load_module
    top_module = self._load_package(package, submodules=submodules)
  File "/Users/m/.local/share/virtualenvs/griffe-bug-j_gvc5DW/lib/python3.10/site-packages/griffe/loader.py", line 346, in _load_package
    top_module = self._load_module(package.name, package.path, submodules=submodules)
  File "/Users/m/.local/share/virtualenvs/griffe-bug-j_gvc5DW/lib/python3.10/site-packages/griffe/loader.py", line 362, in _load_module
    return self._load_module_path(module_name, module_path, submodules, parent)
  File "/Users/m/.local/share/virtualenvs/griffe-bug-j_gvc5DW/lib/python3.10/site-packages/griffe/loader.py", line 390, in _load_module_path
    self._load_submodules(module)
  File "/Users/m/.local/share/virtualenvs/griffe-bug-j_gvc5DW/lib/python3.10/site-packages/griffe/loader.py", line 395, in _load_submodules
    self._load_submodule(module, subparts, subpath)
  File "/Users/m/.local/share/virtualenvs/griffe-bug-j_gvc5DW/lib/python3.10/site-packages/griffe/loader.py", line 406, in _load_submodule
    member_parent[subparts[-1]] = self._load_module(
  File "/Users/m/.local/share/virtualenvs/griffe-bug-j_gvc5DW/lib/python3.10/site-packages/griffe/mixins.py", line 83, in __setitem__
    self.members[parts[0]][parts[1:]] = value  # type: ignore[attr-defined]
KeyError: 'some'

Expected behavior
Name for .py files with more then one dot symbol works

System (please complete the following information):

• griffe version: 0.22.0
• Python version: 3.10.1
• OS: [Mac]

Additional context
Encountered this behavior using mkdocs with mkdocstrings and python handler to generate
documentation for project with fastapi api's with a lot of gunicorn.conf.py

[pawamoy]

Hello, thanks for the report.

Is there any benefit in naming the file gunicorn.conf.py rather than gunicorn_conf.py for example. Is it the file name expected by Gunicorn itself?

[MikhailPasechnik]

Unfortunately yes:(

From the official documentation:

The third source of configuration information is an optional configuration file gunicorn.conf.py searched in the current working directory...

https://docs.gunicorn.org/en/stable/configure.html

[pawamoy]

I've pushed a fix that simply skip modules with dots in their names.