Player cannot collect items in EnderDragon hitbox

The player cannot collect items in the hitbox of the EnderDragon.

How to reproduce

1. Use the following command (uses the bug reported in MC-90417):

   /summon Boat ~ ~ ~ {Passengers:[{id:EnderDragon}]}

2. Drop an item near the EnderDragon

3. Try to collect the item

The item is not a ghost item, once the EnderDragon moved away the player is able to pick the item up.