mathlib3

4c1d12f5 - feat(data/complex/basic): Adding `im_eq_sub_conj` (#5750)

feat(data/complex/basic): Adding `im_eq_sub_conj` (#5750) Adds `im_eq_sub_conj`, which I couldn't find in the library. Co-authored-by: Rob Lewis <Rob.y.lewis@gmail.com>