Release v1.8.1

Fixed issues

• a deprecation with numpy>= 1.24 (eg np.bool and np.str), related to #393

Additions

• the baseAgent class now has two new template methods save_state and load_state to save and
  load the agent's state during Grid2op simulations. Examples can be found in L2RPN baselines (PandapowerOPFAgent and curriculumagent).

Improvments

• improved error messages in pandapower backend when the grid do not converge due to disconnected generators or loads.