ventura_upgrade_supported.py and sonoma_upgrade_supported.py are returning False on vm's

[SoxIn4]

I'm not in a position to make a pull request right now, but I found that the monterey version has this at the top of its sysctl function, and it's missing in the newer versions:

munki-facts/facts/monterey_upgrade_supported.py

Lines 63 to 64 in 0ed30ec

	if isinstance(name, str):
	name = name.encode('utf-8')

Adding that to the new versions seems to work in my local testing. (Can't test for real until Wed.)

[gregneagle]

Untested, but 9784266 should address.