If you know vanilla tweak "silece mob" datapack, basically is the same function except you remove the AI from a Mob, to do that:
RENAME A MOB TO "noAI"

This datapack will allow you to keep a mob without their AI, that means it wont move but still will die and make sounds, you can use it to decorate and add mobs on places so it wont escape or wont attack you.

PD: you can still rename a mob after you remove their AI, e.g. Rename a mob "noAI" and then you can rename it "Dinnerbone" so it will be flipped + noAI.