fix bug in Simulation.eps_bounds with CustomMedium

[tylerflex]

@weiliangjin2021 not sure how this bug got in, but it was breaking plotting with CustomMedium. I think this is the only area that needs fixing but maybe you can confirm. Thanks

[weiliangjin2021]

It seems to be removed in a commit fix errors caught by pylint 2.16.1. Previously it was eps_min = min(eps_min, min(eps_component.real.values.ravel())).

[weiliangjin2021]

do you think np.min(eps_component.real.values.ravel()) will somtimes return dataarray type so that it will error at min(float, dataarray)? It occurs here

tidy3d/tidy3d/components/medium.py

Line 452 in 0cf25fe

float(np.min(eps_array.real))

when float is removed.

[tylerflex]

do you think np.min(eps_component.real.values.ravel()) will somtimes return dataarray type so that it will error at min(float, dataarray)?

Isn't .values always a np.ndarray? or can it be a dataarray?

[weiliangjin2021]

You are right. Feel free to merge.