Add check for macOS version 12

[apizz]

Since the AssetCacheLocatorUtil binary is part of macOS Sierra, add check to ensure machines running versions less than 12 don't attempt to run the command.

[bmike]

To be clear - I'd still merge this change. It fails less often in 10.10 through 10.13 and still fails the same with the same error as the original script for 10.9 and older OS.

[apizz]

wew this is old ... maybe it's time she merges :)