fix: conditional export for before dart 3.3

Author: YumNumm

packages/yet_another_json_isolate/lib/yet_another_json_isolate.dart

@@ -1,3 +1,5 @@
 library yet_another_json_isolate;
 
-export 'src/_isolates_io.dart' if (dart.library.js_interop) 'src/_isolates_web.dart';
+export 'src/_isolates_io.dart'
+    if (dart.library.js_interop) 'src/_isolates_web.dart' // After Dart 3.3
+    if (dart.library.js) 'src/_isolates_web.dart'; // Before Dart 3.3 (for backwards compatibility)