I actually started making this and the only thing left is that the enemy’s still do the animation of the cinematic finisher. But Geralt is fine and there’s no cinematic.
There is a mod that does exactly you want. It's called "Better Combat Animations" https://www.nexusmods.com/witcher3/mods/2538
All you need to do is download the optional file called "Disable Cinematif Kill Cam" & done. That is a must have mod for me.