fix: 중복 코드 제거

Author: yewonJin

apps/frontend/src/app/main.tsx

@@ -3,13 +3,10 @@ import { createRoot } from "react-dom/client";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { RouterProvider, createRouter } from "@tanstack/react-router";
 import "../shared/index.css";
-import "../shared/index.css";
 import { routeTree } from "@/routeTree.gen";
 
 const queryClient = new QueryClient();
 
-const queryClient = new QueryClient();
-
 const router = createRouter({ routeTree });
 declare module "@tanstack/react-router" {
   interface Register {