Fix: Buttons no longer work on the TreeView element when the element …

…is selected.

src/Avalonia.Xaml.Interactions.DragAndDrop/ContextDragBehavior.cs

@@ -144,6 +144,7 @@ private void AssociatedObject_PointerPressed(object? sender, PointerPressedEvent
                 _captured = true;
             }
         }
+        e.Handled = false;
     }
 
     private void AssociatedObject_PointerReleased(object? sender, PointerReleasedEventArgs e)