Add version dummy to interface

qutil/__init__.pyi

@@ -3,6 +3,8 @@ described in https://scientific-python.org/specs/spec-0001."""
 import pathlib
 import importlib
 
+__version__ = "typing_interface_version_dummy"
+
 __all__ = []
 for path in pathlib.Path(__file__).parent.glob('*'):
     if not path.stem.startswith('_'):