sis_hash_helper/get_object_state fails for Numpy arrays

[albertz]

I think in earlier Sisyphus versions, it would not throw an exception, but dangerously just ignore the content of the Numpy array. Now in the latest Sisyphus version, it catches this as a problem, and fails with the exception:

AssertionError('Failed to get object state of: array([1, 5])')

[albertz]

Actually this seems to be a duplicate of #165? (cc @NeoLegends)