fix: update demo_mode assignment in GenericAgentArgs class (#175)

Author: recursix

src/agentlab/agents/generic_agent/generic_agent.py

@@ -43,7 +43,7 @@ def set_benchmark(self, benchmark: bgym.Benchmark, demo_mode):
 
         # verify if we can remove this
         if demo_mode:
-            self.action_set.demo_mode = "all_blue"
+            self.flags.action.action_set.demo_mode = "all_blue"
 
     def set_reproducibility_mode(self):
         self.chat_model_args.temperature = 0