The player can damage their own mount with Riptide

The player is able to damage their own mount with Riptide (confirmed with nautili and horses; does not happen with boats). It would be expected that either the player cannot use Riptide while in a vehicle or that they could not damage their mount by doing so.

To reproduce

1. /weather rain

2. /summon minecraft:horse ~ ~ ~ {Tame:1b,equipment:{saddle:{id:"saddle"}}}

3. /give @s minecraft:trident[minecraft:enchantments={"riptide":3}]

4. Ride the horse

5. Use riptide while facing any direction
   ❌ The horse takes damage

Expected result

Either the horse would not take damage or the player would not have been able to use Riptide while riding it.