Fix: Fixed loading icons in Properties Customize page (#11543)

Author: hishitetsu

src/Files.App/ViewModels/Properties/CustomizationViewModel.cs

@@ -88,9 +88,10 @@ await App.Window.DispatcherQueue.EnqueueAsync(() =>
 		public void LoadIconsForPath(string path)
 		{
 			IconResourceItemPath = path;
+			_dllIcons.Clear();
 
 			var icons = Win32API.ExtractIconsFromDLL(path);
-			if (icons.Count == 0)
+			if (icons?.Count is null or 0)
 				return;
 
 			foreach(var item in icons)