mac-capture: Add label about missing audio on macOS 12 to SCK

plugins/mac-capture/data/locale/en-US.ini

@@ -21,3 +21,4 @@ Crop.origin.y="Crop top"
 Crop.size.width="Crop right"
 Crop.size.height="Crop bottom"
 SCKCapture="macOS Screen Capture"
+SCKAudioUnavailable="Audio capture requires macOS 13 or newer."

plugins/mac-capture/mac-screen-capture.m

@@ -1084,6 +1084,13 @@ static obs_properties_t *screen_capture_properties(void *data)
 
 	content_changed(sc, props);
 
+	if (@available(macOS 13.0, *))
+		;
+	else
+		obs_properties_add_text(props, "audio_info",
+					obs_module_text("SCKAudioUnavailable"),
+					OBS_TEXT_INFO);
+
 	return props;
 }