Well I guess the question as been answered so I can accept your answer.
But this is something I don't really understand... When I was coding my own engine (with SFML), the driver was never forcing V-Sync and the framerate was never locked unless explicitly specified. So why is this the case with Godot Engine ? There must be something to do in the engine itself to change that, right ?
(btw, I'm using Xubuntu, not Windows and I could maybe change something in my driver but I would rather use something specific to my game project in order to not affect anything else and have the change carried with the game if I give it to coworkers)