Let autoapi also discover all _os.py modules

When working on the extension, I was made aware that the `_os.py` files
where never parsed by autoapi. Meaning the links for the supported
Operating Systems would not work. This fix resolves that issue

Author: Miauwkeru

docs/source/conf.py

@@ -15,6 +15,8 @@
 import sys
 from pathlib import Path
 
+from sphinx.application import Sphinx
+
 sys.path.insert(0, os.path.abspath("./contributing"))
 
 for path in map(str, Path("../../submodules/").resolve().iterdir()):
@@ -179,3 +181,14 @@
     # https://github.com/sphinx-doc/sphinx/issues/4961
     "ref.python",
 ]
+
+
+def do_not_skip_os_classes(app: Sphinx, what: str, name: str, obj, skip: bool, options: list[str]) -> bool:
+    if name.endswith("._os") and what == "module":
+        skip = False
+    return skip
+
+
+def setup(sphinx: Sphinx) -> None:
+    if "autoapi.extension" in extensions:
+        sphinx.connect("autoapi-skip-member", do_not_skip_os_classes)