fix(agent): sync tool group updates for existing agents

Author: Alexxigang

agentscope-core/src/main/java/io/agentscope/core/ReActAgent.java

@@ -1740,4 +1740,4 @@ private void configureSkillBox(Toolkit agentToolkit) {
             hooks.add(new SkillHook(skillBox));
         }
     }
-}
+}