What Should Happen

The /execute on owner subcommand should select the owner of a horse, donkey, llama, or mule.

Steps to Reproduce

1. Spawn in and tame a horse
2. Keep riding the horse
3. Run the command /execute on vehicle on owner run say I own this horse
4. The chat will not display anything

Note that this behaviour shouldn't be expected from camels, skeleton horses, nor zombie horses. Those don't have the owner tag that the others do