Mchirp bin probabilities do not sum to 1

@leo-singer here is an example of an event where the bins do not sum to one: https://gracedb.ligo.org/events/G573305/view/ This was discussed in the LL call on 6/18, this is the function you provided originally: https://git.ligo.org/emfollow/em-properties/cgmi/-/blob/main/ligo_cgmi/chirp_probabilities.py?ref_type=heads#L58

An easy fix would be to re-normalize, but it is good to confirm the sky map and function are behaving as intended.