Log Message:
py-ordered-set: updated to 4.1.0

Version 4.1 (January 2022)

Packaged using flit. Wheels now exist, and setuptools is no longer required.
This package now has a typical package structure, instead of being a single \ 
module. The code is in ordered_set/__init__.py instead of ordered_set.py.
There is an ordered_set/py.typed so that type checkers know about the types.
Use the type aliases SetLike[T] and OrderedSetInitializer[T] to simplify some types.
Updated the way overloaded type signatures are written to what MyPy currently \ 
expects.
Minimum Python version is 3.7.