feat(measure_theory/group/arithmetic): add `has_measurable_smul.op` and `has_measurable_smul₂.op` (#12196)
feat(measure_theory/group/arithmetic): add `has_measurable_smul.op` and `has_measurable_smul₂.op` (#12196)

This matches the naming of `has_continuous_smul.op`.





leanprover-community/mathlib,leanprover-community/mathlib