Pets are added to their owner's team as well when using /team join

When using /team join on a player, all pets of that player will automatically be added to the team as well, however they don't appear in the /team list command. This is probably intentional, but it seems unexpected.

To reproduce

1. Pet an animal

2. /team add testTeam

3. /team join testTeam @s

   → The message says that only you were added to the team, but your pets were as well.

4. /team list testTeam

   → Only you are in the team

5. /say @e[team=testTeam]

   → You and your pets are listed.