fix(python): Do math on monotonic clocks only

[SyntaxColoring]

Overview

A lot of Python code (in various projects) was doing stuff like:

start = time.now()
do_stuff()
end = time.now()
duration = end - start

That's not quite right because time.now() can be affected by things like daylight savings time, leap seconds, and NTP adjustments. If we're doing math on timestamps, it needs to come from a monotonic clock. So this switches all (or at least most) of those places to use time.monotonic() instead.

Test Plan and Hands on Testing

None.

Changelog

Basically a global Ctrl+F for time.time(). I replaced it with time.monotonic() when it was obvious to me that it was only used in the local scope and that math was being done on it. So this excludes things like time() calls that were getting saved in CSV reports.

Review requests

OK with all the hardware-testing changes, or do I need to run that by anybody?

Risk assessment

Low. Changes are trivial.

[mjhuff]

Yeah, most definitely. Thank you!