Cache python package

[erikng]

Building the python package takes a long time. We should use artifact storage, check if the storage is still there and then use it.

https://docs.github.com/en/enterprise-cloud@latest/actions/using-workflows/storing-workflow-data-as-artifacts

[gregneagle]

Since the Python package is no longer part of Munki 7, I'd recommend closing this as "won't do"