pyFAI 2023.2 breaks the CalibrateMulti task

Traceback: https://gitlab.esrf.fr/workflow/ewoksapps/ewoksxrpd/-/jobs/577307

Summary of the code in CalibrateMulti

calibrant = pyFAI.calibrant.get_calibrant("...")
setup = pyFAI.goniometer.GoniometerRefinement(
    initial_guess,
    pos_function=lambda x: x,
    trans_function=trans_function,
    detector=detector,
    wavelength=wavelength0,
)
for i, (image, xi) in enumerate(zip(self.inputs.images, self.inputs.positions)):
    label = f"position{i}"
    setup.new_geometry(label, image=image, metadata=xi, calibrant=calibrant)
for setup_single_dist in setup.single_geometries.values():
    setup_single_dist.extract_cp()  <<< FAILS with IndexError

Code in pyfai that fails

    def extract_cp(self, max_rings=None, pts_per_deg=1.0, Imin=0):
        tth = numpy.array([i for i in self.calibrant.get_2th() if i is not None])  <<< "Cannot calculate 2theta angle without knowing wavelength"
        ...
        tth_max[-1] = delta[-1]  <<< IndexError

This commit causes the error:

class SingleGeometry(object):
    """This class represents a single geometry of a detector position on a
    goniometer arm
    """

    def __init__(self, ...):
            ...
            dict_geo["wavelength"] = self.calibrant.wavelength  <<< THIS CHANGED, commenting it makes everything work again

Providing the wavelength to GoniometerRefinement used to be enough. Now it also has to be provided to the calibrant object? @jerome.kieffer Can you comment?