Lightning does not reset copper golem oxidation

Unlike unwaxed copper blocks, an unwaxed copper golem does not reset its oxidation when struck by lightning.

Steps to reproduce:

1. Place a carved pumpkin on top of an unwaxed oxidized copper block

2. Run the command:

   /execute at @n[type=copper_golem] run summon lightning_bolt

3. Notice the copper chest has reset its oxidation, but the copper golem has not