Python 3.8 End of Life

[amcintosh]

PSA that python 3.8 went EOL on October 31, 2024.

I have no plans to immediately drop support at that time. However Python versions earlier than 3.9 lack the zoneinfo module that implements PEP 615, which means that we are using a backport library for those Python versions. We will likely discontinue that usage at some point in the future. When we do we we'll drop support for Python<3.9 in a new major release.