Fixed pytest_ignore_collect not to block default pytest code (#464)

Fixed `pytest_ignore_collect` hook implementation to return `None` rather than `False` when the path ought not to be ignored.  This is necessary to enable the default pytest implementation of `pytest_ignore_collect()` to be used.  Otherwise, the default rules are never applied and e.g. `--ignore` does not work.

docs/versionhistory.rst

@@ -22,6 +22,9 @@ This library adheres to
 - Fixed checks against annotations wrapped in ``NotRequired`` not being run unless the
   ``NotRequired`` is a forward reference
   (`#454 <https://github.com/agronholm/typeguard/issues/454>`_)
+- Fixed the ``pytest_ignore_collect`` hook in the pytest plugin blocking default pytest
+  collection ignoring behavior by returning ``None`` instead of ``False``
+  (PR by @mgorny)
 
 **4.4.0** (2024-10-27)
 

tests/conftest.py

@@ -13,14 +13,16 @@
 pytest_plugins = ["pytester"]
 
 
-def pytest_ignore_collect(collection_path: Path, config: pytest.Config) -> bool:
+def pytest_ignore_collect(
+    collection_path: Path, config: pytest.Config
+) -> typing.Optional[bool]:
     match = version_re.search(collection_path.name)
     if match:
         version = tuple(int(x) for x in match.groups())
         if sys.version_info < version:
             return True
 
-    return False
+    return None
 
 
 @pytest.fixture