fix perf issue in schedule builder

Author: marcoacierno

backend/custom_admin/src/components/schedule-builder/placeholder.tsx

@@ -85,8 +85,7 @@ export const Placeholder = ({
       }}
     >
       {isMovingItemLoading && <span>Please wait</span>}
-      {!isMovingItemLoading && !canDrop && <span>Click to add</span>}
-      {!isMovingItemLoading && canDrop && <span>Drop here to move</span>}
+      {!isMovingItemLoading && <span>Drop / Add</span>}
       <PlusIcon />
     </div>
   );

backend/custom_admin/src/components/schedule-builder/root.tsx

@@ -20,7 +20,9 @@ export const ScheduleBuilderRoot = ({
       }}
     >
       <AddItemModalProvider>
-        <ScheduleBuilder />
+        <DjangoAdminLayout>
+          <ScheduleBuilder />
+        </DjangoAdminLayout>
       </AddItemModalProvider>
     </Base>
   );
@@ -39,7 +41,7 @@ const ScheduleBuilder = () => {
   } = data ?? { conference: {} };
 
   return (
-    <DjangoAdminLayout>
+    <>
       {loading && <h2>Please wait</h2>}
       {!loading && error && (
         <h2>Something went wrong. Make sure you have the right permissions.</h2>
@@ -52,6 +54,6 @@ const ScheduleBuilder = () => {
           <PendingItemsBasket />
         </>
       )}
-    </DjangoAdminLayout>
+    </>
   );
 };