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

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

packages/stream_chat_flutter/lib/src/system_message.dart

@@ -11,10 +11,10 @@ typedef SystemMessage = StreamSystemMessage;
 class StreamSystemMessage extends StatelessWidget {
   /// Constructor for creating a [StreamSystemMessage]
   const StreamSystemMessage({
-    Key? key,
+    super.key,
     required this.message,
     this.onMessageTap,
-  }) : super(key: key);
+  });
 
   /// This message
   final Message message;
@@ -28,11 +28,7 @@ class StreamSystemMessage extends StatelessWidget {
     final theme = StreamChatTheme.of(context);
     return GestureDetector(
       behavior: HitTestBehavior.opaque,
-      onTap: () {
-        if (onMessageTap != null) {
-          onMessageTap!(message);
-        }
-      },
+      onTap: onMessageTap == null ? null : () => onMessageTap!(message),
       child: Text(
         message.text!,
         textAlign: TextAlign.center,