indicate that OMPython includes type hints via py.typed

see: https://mypy.readthedocs.io/en/stable/installed_packages.html#installed-packages
see: https://blog.whtsky.me/tech/2021/dont-forget-py.typed-for-your-typed-python-package/
see: https://stackoverflow.com/questions/76073605/add-py-typed-as-package-data-with-setuptools-in-pyproject-toml

Author: syntron

OMPython/py.typed

@@ -25,6 +25,9 @@ dependencies = [
 [tool.setuptools]
 packages = ["OMPython"]
 
+[tool.setuptools.package-data]
+"OMPython" = ["py.typed"]
+
 [project.urls]
 Homepage = "http://openmodelica.org/"
 Documentation = "https://openmodelica.org/doc/OpenModelicaUsersGuide/latest/ompython.html"