why no windows whl for py38 and py39?

[Whitney Jackson]

While there are windows builds for python 3.7 and earlier on pypi, it looks like there aren't any for python 3.8 and python 3.9. Is that on purpose? If so what's the easiest way to get a C++ accelerated wheel for Windows and python 3.8 and python 3.9? 

List of python file on pypi: https://pypi.org/project/protobuf/#files

Thanks!