Update kSizedBoxEmpty

lib/screens/envvar/environments_pane.dart

@@ -153,7 +153,7 @@ class EnvironmentsList extends HookConsumerWidget {
                           ),
                         );
                       }
-                      return const SizedBox();
+                      return kSizedBoxEmpty;
                     }).toList(),
                   ),
           ),

lib/screens/home_page/collection_pane.dart

@@ -190,7 +190,7 @@ class _RequestListState extends ConsumerState<RequestList> {
                     ),
                   );
                 }
-                return const SizedBox();
+                return kSizedBoxEmpty;
               }).toList(),
             ),
     );