Zombies that spawn holding spears and can pick up loot swap their spear for any other item

Zombies, husks, drowned, and zombie villagers that are holding spears and can pick up loot pick up any dropped item and discard their spear. Without commands, this is only visible with zombies and husks.

How to reproduce:

1. Execute the following command:

   /summon minecraft:zombie ~ ~ ~ {equipment:{mainhand:{id:"minecraft:iron_spear"}},CanPickUpLoot:1b}

2. Drop an item towards the zombie you summoned.
   -> ❌ The zombie eventually picks it up and discards its spear.

Expected result:

Zombies, husks, drowned, and zombie villagers would prefer spears over items that cannot be used as weapons.

Observed result:

Zombies, husks, drowned, and zombie villagers do not prefer spears over other items, causing them to discard their spear if a different item is dropped near them.