Simplify process_*.py scripts via utilization of the new shared memory features of Python 3.8

[monocongo]

We currently have our own shared memory solution cooked up, but it may be more elegant to use the new shared memory module provided by the upcoming Python 3.8 release. Hopefully replacing what we currently have with this new mechanism for sharing memory across processes will result in less code, increasing the readability and maintainability of these scripts.