Not only is it not forbidden in France, in tech at least it is expected that you put a picture.
Yes it's also allowed not to put one (and illegal to discriminate because it's not here), but from my experience most people do.
(source: graduated there)
I'm pretty sure I was told at school to never include a picture, but that was more than a decade ago. Today I see most resumes having pictures, especially those from Epitech candidates.
I don't like it though, I don't see how a picture is relevant to a resume.
It's absolutely not. Most of my friends put a picture.
I'm in tech and I don't but that's a personal choice.