[CHIA-4390] [BUG] harvester locks up and will not respond to restarts or kills

Harvester will not respond nor will it continue to harvest plots, restart commands get a timeout error and render the process defunct. Sending kill commands to the process or its parents do not kill it. From the logs it appears that the harvester delays started to increase every epoch until reaching around 200 seconds when the system locked up. Removing the 4 drives most prone to long lookups has resolved the issue so far.

Steps to reproduce the behavior:

Run harvester on large number of plots with a few questionable drives that may have 30+ second lookups.

Expected behavior Process times out after passing a threshold of unwinability on a blocking lookup. rather than sitting and waiting indefinitely for the drive.

• OS: Ubuntu 20.04
• CPU: i5-6500