Show delete drag target only in design mode

lib/pages/design_component.dart

@@ -418,6 +418,7 @@ class DesignComponentPage extends HookWidget {
                   // disposeController: false,
                   backgroundColor: Theme.of(context).colorScheme.background,
                 ),
+                if (!isSimulating.value) 
                   Positioned(
                     bottom: 0,
                     right: 0,
@@ -438,7 +439,7 @@ class DesignComponentPage extends HookWidget {
                         ),
                       ),
                     ),
-                )
+                  ),
               ],
             ),
           );