mathlib3

9eb78a33 - feat(measure_theory/function/ae_eq_fun): generalize scalar actions (#12248)

feat(measure_theory/function/ae_eq_fun): generalize scalar actions (#12248) This provides a more general `has_scalar` instance, along with `mul_action`, `distrib_mul_action`, `module`, `is_scalar_tower`, `smul_comm_class`, and `is_central_scalar` instances.