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/create/vm.go

@@ -28,6 +28,7 @@ var netSoftnetBlock []string
 var netBridged string
 var headless bool
 var nested bool
+var noAudio bool
 var suspendable bool
 var username string
 var password string
@@ -70,6 +71,7 @@ func newCreateVMCommand() *cobra.Command {
 	command.Flags().StringVar(&netBridged, "net-bridged", "", "whether to use Bridged network mode")
 	command.Flags().BoolVar(&headless, "headless", true, "whether to run without graphics")
 	command.Flags().BoolVar(&nested, "nested", false, "enable nested virtualization")
+	command.Flags().BoolVar(&noAudio, "no-audio", false, "disable audio pass-through to the host")
 	command.Flags().BoolVar(&suspendable, "suspendable", false, "treat the VM as suspendable, "+
 		"disabling certain devices for suspendability support and issuing \"tart suspend\" instead of \"tart stop\" "+
 		"when VM's specification is updated, thus preserving the VM's state between specification generations")
@@ -156,6 +158,7 @@ func runCreateVM(cmd *cobra.Command, args []string) error {
 		NetBridged:   netBridged,
 		Headless:     headless,
 		Nested:       nested,
+		NoAudio:      noAudio,
 		Username:     username,
 		Password:     password,
 		RandomSerial: randomSerial,