Remove intentFlags from FlutterWebAuth2Options

Removed the 'intentFlags' parameter from FlutterWebAuth2Options.

Author: Namaneo

templates/flutter/lib/src/client_io.dart.twig

@@ -335,7 +335,6 @@ class ClientIO extends ClientBase with ClientMixin {
           ? callbackUrlScheme
           : "{{spec.title | caseLower}}-callback-${config['project']!}",
       options: const FlutterWebAuth2Options(
-        intentFlags: ephemeralIntentFlags,
         useWebview: false,
       ),
     ).then((value) async {