fix: Werewolf Game

- As all the roles in werewolf game as `react_mode` =
  `RoleReactMode.REACT`, so `role._react()` will be called everytime.
- When not returning anything from `role._think()` => Therefore,
  `role._act()` will not be executed.
- Due to which this issue was comming: https://github.com/geekan/MetaGPT/issues/1313

metagpt/ext/werewolf/roles/base_player.py

@@ -86,6 +86,7 @@ class BasePlayer(Role):
             # FIXME: hard code to split, restricted为"Moderator"或"Moderator, 角色profile"
             # Moderator加密发给自己的，意味着要执行角色的特殊动作
             self.rc.todo = self.special_actions[0]()
+        return self.rc.todo is not None
 
     async def _act(self):
         # todo为_think时确定的，有两种情况，Speak或Protect

metagpt/ext/werewolf/roles/moderator.py

@@ -171,6 +171,7 @@ class Moderator(BasePlayer):
         else:
             # 上一轮消息是游戏角色的发言，解析角色的发言
             self.rc.todo = ParseSpeak()
+        return self.rc.todo is not None
 
     def _init_fields_from_obj(self, obs: dict[str, Union[int, str, list[str]]]):
         self.game_setup = obs.get("game_setup", "")

metagpt/ext/werewolf/roles/werewolf.py

@@ -13,3 +13,4 @@ class Werewolf(BasePlayer):
         await super()._think()
         if isinstance(self.rc.todo, Speak):
             self.rc.todo = Impersonate()
+        return self.rc.todo is not None

metagpt/ext/werewolf/roles/witch.py

@@ -26,3 +26,4 @@ class Witch(BasePlayer):
                 self.rc.todo = Poison()
             else:
                 raise ValueError("Moderator's instructions must include save or poison keyword")
+        return self.rc.todo is not None