Python 3.8 End of Life

[amcintosh]

PSA that python 3.8 goes EOL as of October 31, 2024.

We 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 will drop support for Python<3.9 in a new major release.