gripper agent crashed when actuator controller has modbus error

[ykyohei]

This happened in satp3 twice so far. monitor_state crashes by following error.
We can resolve controller modbus error by power cycling it. but agent doesn't need to crash.
We should be able to make agent robust against this issue.

2025-03-11T22:37:44+0000 monitor_state:4 Status is now "running".
2025-03-11T22:37:44+0000 monitor_state:4 Status is now "starting".
2025-03-11T22:37:44+0000 start called for monitor_state
2025-03-11T22:31:16+0000 monitor_state:3 Status is now "done".



]
/opt/venv/lib/python3.10/site-packages/socs/agents/hwp_gripper/agent.py:768:monitor_state
/opt/venv/lib/python3.10/site-packages/ocs/ocs_agent.py:984:_running_wrapper
/opt/venv/lib/python3.10/site-packages/twisted/python/context.py:82:callWithContext
/opt/venv/lib/python3.10/site-packages/twisted/python/context.py:117:callWithContext
/opt/venv/lib/python3.10/site-packages/twisted/python/threadpool.py:285:<lambda>
/opt/venv/lib/python3.10/site-packages/twisted/python/threadpool.py:269:inContext
2025-03-11T22:31:16+0000 monitor_state:3 CRASH: [Failure instance: Traceback: <class 'TypeError'>: unhashable type: 'dict'