cocoa-cb: fix quit in fs with none native fs

since the none native fs is a special legacy case it needs a special
quit routine. it indefinitely waited for an exit fs screen event to
shutdown properly, though that event only fires for the native fs.
now we check if we really are using a native fullscreen and if not
shutdown immediately.

Fixes #6704

video/out/cocoa_cb_common.swift

@@ -524,7 +524,8 @@ class CocoaCB: NSObject {
     }
 
     func shutdown(_ destroy: Bool = false) {
-        isShuttingDown = window?.isAnimating ?? false || window?.isInFullscreen ?? false
+        isShuttingDown = window?.isAnimating ?? false ||
+                         window?.isInFullscreen ?? false && mpv.getBoolProperty("native-fs")
         if window?.isInFullscreen ?? false && !(window?.isAnimating ?? false) {
             window?.close()
         }