Remove unused arguments from pytest hook to indirectly address warnings

The warnings are about the use of the deprecated `startdir` argument

idaes_examples/notebooks/conftest.py

@@ -175,6 +175,6 @@ def pytest_collection_modifyitems(session, config, items: list):
 
 
 @pytest.hookimpl(trylast=True)
-def pytest_report_collectionfinish(config, start_path, startdir, items):
+def pytest_report_collectionfinish(config):
     print_hook(config, "pytest_report_collectionfinish")
     return NotebookPrep.report()