✨(demo) upgrade demo app

Add the locale switching feature.

apps/demo/src/main.tsx

@@ -1,13 +1,10 @@
 import React from "react";
 import ReactDOM from "react-dom/client";
 import "./index.scss";
-import { CunninghamProvider } from "@openfun/cunningham-react";
 import { App } from "./App";
 
 ReactDOM.createRoot(document.getElementById("root") as HTMLElement).render(
   <React.StrictMode>
-    <CunninghamProvider>
-      <App />
-    </CunninghamProvider>
+    <App />
   </React.StrictMode>
 );