[ci] Drop redundant question marks used with dynamic. (#3756)

Fixes flutter/flutter#79089

Author: aam

packages/google_sign_in/google_sign_in_web/lib/src/generated/gapi.dart

@@ -19,11 +19,11 @@ import 'package:js/js.dart';
 
 // Module gapi
 typedef void LoadCallback(
-    [dynamic? args1,
-    dynamic? args2,
-    dynamic? args3,
-    dynamic? args4,
-    dynamic? args5]);
+    [dynamic args1,
+    dynamic args2,
+    dynamic args3,
+    dynamic args4,
+    dynamic args5]);
 
 @anonymous
 @JS()

packages/in_app_purchase/in_app_purchase/lib/src/in_app_purchase/in_app_purchase_connection.dart

@@ -304,5 +304,5 @@ class IAPError {
   final String message;
 
   /// Error details, possibly null.
-  final dynamic? details;
+  final dynamic details;
 }