Dispenser using spawn egg spawns mob too high

The bug

When a dispenser uses a spawn egg to spawn a mob, the mob is spawned 1 block too high.

How to reproduce

1. Give yourself some spawn eggs

   /give @s minecraft:pig_spawn_egg{EntityTag:{NoGravity:1b}} 64
   

2. Place an upwards facing dispenser and place the spawn eggs inside it
3. Power the dispenser
   The pig is spawned 1 block too high