Only show traffic lights with full system decorations.

Fixes second part of #10650.

native/Avalonia.Native/src/OSX/WindowImpl.mm

@@ -614,7 +614,8 @@ void WindowImpl::UpdateStyle() {
     }
 
     bool wantsChrome = (_extendClientHints & AvnSystemChrome) || (_extendClientHints & AvnPreferSystemChrome);
-    bool hasTrafficLights = _isClientAreaExtended ? wantsChrome : _decorations == SystemDecorationsFull;
+    bool hasTrafficLights = (_decorations == SystemDecorationsFull) &&
+        (_isClientAreaExtended ? wantsChrome : true);
     
     NSButton* closeButton = [Window standardWindowButton:NSWindowCloseButton];
     NSButton* miniaturizeButton = [Window standardWindowButton:NSWindowMiniaturizeButton];