Fix builds about python-workshop

[dopplershift]

I think @kgoebber may have fixed some things like this in the gallery.

[kgoebber]

Yes, these are both GFS FV3 related with differing number of vertical levels between Temp/Geopotential Height vs. Relative Humidity/Wind Components. The following code is taken from the python gallery isentropic example. It uses newer NumPy to find the common index values between two arrays (levels for wind components and levels for geopotential heights). The result gives the index values of the geopotential height array since it has more vertical levels than the wind component arrays. This list can then be used to subset the geopotential height array to have the same number of vertical levels for both arrays.

# Due to a different number of vertical levels find where they are common
_, _, common_ind = np.intersect1d(lev_uwnd, lev_hght, return_indices=True)