Version 2.2 beta 2 can no longer share files with older macOS systems

[RolfKocherhans]

VirtualBuddyGuest.app vers. 2.2 does not run in Ventura (13.7.8) any more, I had to revert to
VirtualBuddy 2.1 to be able to transfer files between host and VM.

[insidegui]

The minimum OS version of the guest app currently follows the one for VirtualBuddy itself, and VirtualBuddy has recently raised that to macOS 14. I'm working on a mechanism to keep older versions of the guest app available for those situations.