Fix parameter type and graph exception bug

[ShangGaogit]

Summary

This PR fixes two bugs:

1. Several annotations in graph_mpc_fluxonium_1d.py were incorrect. They are of type list, not int.
2. In graph.py, when trying to catch different types of exceptions, the syntax was incorrect. In Python, we can't use and to combine exception types in an except clause. The correct syntax should be except (KeyError, IndexError): with parentheses and commas.

Testing

Jupyter notebook scripts such as fluxonium_mpcoupling_6q_x.ipynb still work.