chore(repo): add lints, update freezed, json_serializable

Signed-off-by: xsahil03x <[email protected]>

packages/stream_chat_flutter/lib/src/date_divider.dart

@@ -13,10 +13,10 @@ typedef DateDivider = StreamDateDivider;
 class StreamDateDivider extends StatelessWidget {
   /// Constructor for creating a [StreamDateDivider]
   const StreamDateDivider({
-    Key? key,
+    super.key,
     required this.dateTime,
     this.uppercase = false,
-  }) : super(key: key);
+  });
 
   /// [DateTime] to display
   final DateTime dateTime;