fix: resolve syntax error in signup_screen caused by redundant closing brace

userfront/lib/features/auth/presentation/signup_screen.dart

@@ -1626,8 +1626,6 @@ class _SignupScreenState extends State<SignupScreen> {
     );
   }
 
-  }
-
   String _buildPolicyDescription() {
     if (_isPolicyLoading) {
       return tr('msg.userfront.signup.policy.loading');