chore: fix conflict between dart:js_interop and json_serializable

See google/json_serializable.dart#1480 for details.

Author: w568w

lib/util/js/js_web.dart

@@ -15,9 +15,12 @@
  *     along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-import 'dart:js_interop/js_interop.dart';
+// fixme: json_serializable conflicts with @JS() annotation in [dart:js_interop]. (https://github.com/google/json_serializable.dart/issues/1391, https://github.com/google/json_serializable.dart/issues/1480)
+// As a workaround, we use the dart:_js_annotations library directly. It should be replaced with [dart:js_interop] when the issue is resolved.
+// ignore: IMPORT_INTERNAL_LIBRARY
+import 'dart:_js_annotations' as js;
 
-@JS('window.eval')
+@js.JS()
 external dynamic eval(dynamic arg);
 
 String evaluate(String jsCode) {