Remove dead comment

This comment explained the 'type: ignore' comment removed in 4ee28b5.

Author: adamchainz

src/pytest_randomly/__init__.py

@@ -213,7 +213,6 @@ def pytest_runtest_teardown(item: Item) -> None:
         _reseed(item.config, 1)
 
 
-# pytest missing type hints for @hookimpl
 @hookimpl(tryfirst=True)
 def pytest_collection_modifyitems(config: Config, items: list[Item]) -> None:
     if not config.getoption("randomly_reorganize"):