Drop Python 3.7 / pycparser and python 3.7

[cjjacks]

Any plans to update the minimum required Python version to 3.8? It seems there are a number of dependencies that rely on Python 3.8 or greater with pycparser being among them. This is causing the test pipeline to fail for the 3.7 build

[nttoole]

Hello @cjjacks , I just checked with @MJJoyce and he agrees that the 3.7 support can/should be dropped.