Minecraft version: 1.12.2
Wizardry version: 4.1.2
Environment: Singleplayer

Issue details: I hit a kind wizard by accident and now thew attack me , is it possible to make them friendly again ?

They'll forget about you if you get far enough away for the chunk to unload.

Yes, that part of their AI works the same way as zombie pigmen so if you go far enough away or respawn it will stop being angry at you.