Scheduled tests failing: gw_example_test.py

https://git.ligo.org/lscsoft/bilby/-/jobs/567308

@moritz.huebner I have a sneaking suspicion due to

>   self._rescale_indexes = [keys.index(element) for element in self.sorted_keys_without_fixed_parameters]
E   ValueError: 'mass_ratio' is not in list

that this has something to do with the MRs that have been put in recently, would you have a few minutes to look at this?