Thank you. I learned to swim with the primary school I was going to, but learning to swim with clothes isn't be part of the official curriculum (as far as I can understand the words of the official website: https://www.education.gouv.fr/bo/2011/28/mene1115402c.htm).
On a pure speculation level, I guess it'd be down to the reasons the two governments mandated the teaching of swimming: for France it's more of a public health/fitness cause (maybe even as a funnel for professional/olympic swimmers), but with no intention to teach swimming as a survival skills, or at least not to the point of including the swim while clothed exercise.
I'm surprised France doesn't have that. It sounds like an important survival skill to me.