fix: update vite config

config aangepast zodat project kan gebuild worden met top-level awaits

frontend/vite.config.ts

@@ -12,4 +12,7 @@ export default defineConfig({
             "@": fileURLToPath(new URL("./src", import.meta.url)),
         },
     },
+    build: {
+        target: 'esnext' //browsers can handle the latest ES features
+      },
 });