Parallelize finding board settings
Parallelize finding board settings

This reduces the _elapsed_ time running the script from ~90s to ~15s
on my AMD Ryzen 7 5700U. The CPU time is still around 2 minutes.

adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython