Umshini: fix minor bug with printing and render_mode (#119)

chatarena/environments/umshini/pettingzoo_wrapper.py

@@ -590,7 +590,7 @@ def step(self, action: str):
             self.render()
 
         # Print final scores if the env has just terminated (debate moderator final message already shows scores)
-        if termination and self.env_name != "debate":
+        if termination and self.env_name != "debate" and self.render_mode is not None:
             print(Fore.BLACK + f"TOTAL SCORES: {self.total_rewards}")
 
         # Get the next agent in PettingZoo, and iterate the underlying environment (used for reward calculations)