fix: mark Home component as async to support await

The example used `await getLogtoContext()` inside a normal function,
which caused a TypeScript error (TS1308). 'await' expressions are only
allowed within async functions and at the top levels of modules.

Marking the Home component as async resolves the error.

Author: jhsong233

docs/quick-starts/framework/next-app-router/_integration.mdx

@@ -121,7 +121,7 @@ import SignIn from './sign-in';
 import SignOut from './sign-out';
 import { logtoConfig } from './logto';
 
-const Home = () => {
+export default async function Home() {
   const { isAuthenticated, claims } = await getLogtoContext(logtoConfig);
 
   return (
@@ -150,9 +150,7 @@ const Home = () => {
       )}
     </nav>
   );
-};
-
-export default Home;
+}
 ```
 
 <Checkpoint />