Refactor and Log NTP drift measurements to a local CSV file

[borland]

Now logs drift measurements to a local CSV file so they can be scooped up into a TeamCity artifact, rather than needing to go look in sumo for the windows event logs

[YuKitsune]

Is this necessary?

[borland]

This is the pet script that claude wrote for me to draw a png file based on ntp-drift.csv. The output looks like this:

It's useful to keep, so we can have a deterministic way of making graphs (rather than asking claude to do it each time), so I saved the script here, even though it's not directly related to the time service.

If you're referring specifically to whether the #!/usr/bin/env python3 line, no, it isn't neccessary, you can run python3 plot_drift.py with or without it. But it's a very common/standard thing for scripts on unix, many python scripts have it, so it seemed fine to me