Fix TypeScript error in tailwind config darkMode setting

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

apps/site/tailwind.config.ts

@@ -1,7 +1,7 @@
 import type { Config } from 'tailwindcss'
 
 export default {
-  darkMode: ["class"],
+  darkMode: "class",
   content: [
     './app/**/*.{ts,tsx}',
     './components/**/*.{ts,tsx}',