Fix allowed_users property in GPTBot

Resolved a syntax error in the allowed_users property within the GPTBot class by adding the missing 'self' parameter. This correction ensures the proper functioning of the property method, enabling the bot to correctly retrieve the list of users authorized to use it.

src/gptbot/classes/bot.py

@@ -89,7 +89,7 @@ class GPTBot:
     # Properties
 
     @property
-    def allowed_users() -> List[str]:
+    def allowed_users(self) -> List[str]:
         """List of users allowed to use the bot.
         
         Returns: