Attempt to import deprecated function "scipy.integrate.simps" in iod/radar/multifitting.py

[gavinhofer]

iod/radar/multifitting.py attempts to import scipy.integrate.simps, which fails because "simps" was renamed to "simpson" in scipy version 1.10.0.

Release notes for v1.10.0
https://docs.scipy.org/doc/scipy-1.10.0/release.1.6.0.html#scipy-integrate-improvements

Even though in the release notes it says the old version was retained for backwards compatibility, it was later removed on 1.14 (scipy/scipy#20278)