Cleanup - Use RemoveAllChildren() over DisposeAllChildren() (#39848)

* Content - change the (should-be-obsolete) DisposeAllChildren into the more robust RemoveAllChildren.

* Remove duplicate calls.

---------

Co-authored-by: ElectroJr <leonsfriedrich@gmail.com>

Content.Client/UserInterface/StatsWindow.xaml.cs

@@ -17,7 +17,7 @@ namespace Content.Client.UserInterface
 
         public void UpdateValues(List<string> headers, List<string[]> values)
         {
-            Values.DisposeAllChildren();
+            Values.RemoveAllChildren();
             Values.Columns = headers.Count;
 
             for (var i = 0; i < headers.Count; i++)