Add --no-audio support to VM spec (#460)

tart run supports --no-audio to disable host audio pass-through, but
there was no way to request it through a VM's spec - Headless, Nested,
and Suspendable all have a flag/field but audio didn't. Useful on
headless hosts with no audio hardware, where audio pass-through can
make guest CoreAudio depend on host audio services that don't exist.

internal/command/get/vm.go

@@ -98,6 +98,7 @@ func runGetVM(cmd *cobra.Command, args []string) error {
 	table.AddRow("Bridged networking interface", nonEmptyOrNone(vm.NetBridged))
 	table.AddRow("Headless mode", vm.Headless)
 	table.AddRow("Nested virtualization", vm.Nested)
+	table.AddRow("Audio disabled", vm.NoAudio)
 	table.AddRow("Status", vm.Status)
 	table.AddRow("Status message", vm.StatusMessage)
 	table.AddRow("Assigned worker", nonEmptyOrNone(vm.Worker))