Horse, donkey, mule, and llama can be tamed while holding item

When trying to tame a horse, you can climb on it even though you re holding an item. In Java Edition, if you hold something the horse doesn't let you hop on it.

This is also inconsistent with the "How to Play" information shown in the screenshot.

Steps to Reproduce:

1. Spawn a horse
2. Hold an item
3. Right click on the horse

Observed Results:
The player mounts the horse.

Expected Results:
The player should only be able to mount the horse if their hand is empty.