`IRamanSpectraWorkChain`: the `IntensitiesAverageWorkChain` is not called correctly

[bastonero]

The function call:

    def run_intensities_averaged(self):
        """Run an `IntensitiesAverageWorkChain` with the calculated vibrational data."""
        self.ctx.intensities_average = AttributeDict({})
        for key, vibrational_data in self.ctx.vibrational_data.items():
            inputs = AttributeDict(self.exposed_inputs(IntensitiesAverageWorkChain, namespace='intensities_average'))
            inputs.vibrational_data = vibrational_data
            inputs.metadata.call_link_label = key

            future = self.submit(IntensitiesAverageWorkChain, **inputs)
            self.report(f'submitting `IntensitiesAverageWorkChain` <PK={future.pk}>.')
            self.to_context(**{f'intensities_average.{key}': future})

calls self.ctx.vibrational_data, which is not set anywhere. So it should be correct to just use self.outputs.vibrational_data.