clean up models

Signed-off-by: dom <githubaccount56556@proton.me>

lib/models_new/pgc/pgc_rank/new_ep.dart

@@ -1,11 +1,9 @@
 class NewEp {
-  String? cover;
   String? indexShow;
 
-  NewEp({this.cover, this.indexShow});
+  NewEp({this.indexShow});
 
   factory NewEp.fromJson(Map<String, dynamic> json) => NewEp(
-    cover: json['cover'] as String?,
     indexShow: json['index_show'] as String?,
   );
 }