PytestDeprecationWarning direct construction has been deprecated

[jaraco]

I see this warning when running against late versions of pytest;

.tox/python/lib/python3.8/site-packages/pytest_checkdocs.py:12
  /Users/jaraco/code/main/jaraco.util/.tox/python/lib/python3.8/site-packages/pytest_checkdocs.py:12: PytestDeprecationWarning: direct construction of CheckdocsItem has been deprecated, please use CheckdocsItem.from_parent
    return CheckdocsItem(path, parent) if path.basename == 'setup.py' else None