Remove duplicated code in `pesummary.gw.conversions.cosmology.z_from_dL_approx`
The purpose of this MR is to remove duplicated code in the pesummary.gw.conversions.cosmology.z_from_dL_approx function.
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The purpose of this MR is to remove duplicated code in the pesummary.gw.conversions.cosmology.z_from_dL_approx function.