try using fix from pytest-dev/pytest#13426

looks lik all good, allows to get rid of horrible conftest hacks!

Author: karlicoss

conftest.py

@@ -26,7 +26,8 @@ optional = []
 
 [dependency-groups]
 testing = [
-    "pytest",
+    "pytest @ git+https://github.com/karlicoss/pytest@pyargs-namespace-packages",
+    # "pytest",
     "ruff",
     "mypy",
     "lxml",  # for mypy html coverage

pyproject.toml

@@ -36,8 +36,6 @@ def fixture() -> Iterator[Path]:
     with TemporaryDirectory() as td:
         root = Path(td)
         shutil.copy(GIT_ROOT / 'pytest.ini', root / 'pytest.ini')
-        shutil.copy(GIT_ROOT / 'conftest.py', root / 'conftest.py')
-        # TODO overwrite consider namesspace pkgs here for now??
         shutil.copytree(THISDIR / 'testdata' / 'src', root / 'src')
         with contextlib_chdir(root):
             yield root