Make arrows of decay (wither arrows) able to be traded on Java as well

On Bedrock edition, you can sometimes find a fletcher villager that sells arrows of decay, which cause the wither effect. These are an interesting, unique item that would be fun to get on Java edition as well.

(Though perhaps it's a bit of a weird way to get these arrows. Mojang could always come up with a new way to get them, but I definitely liked the fact that I could get these items in survival. Maybe bartering with piglins would make more sense, since they hunt wither skeletons.)