Creakings can spawn with doMobSpawning set to false

The Creaking will spawn even when the game rule doMobSpawning is set to false.

How to reproduce:

1. Create a world with the Winter Drop experiment enabled.
2. Execute the following command:

   /gamerule doMobSpawning false

3. Execute the following command:

   /time set night

4. Place a creaking heart between two correctly aligned pale oak logs and wait for the creaking to spawn.

Expected result:

No creakings would be able to spawn when the game rule doMobSpawning is set to false.

Observed result:

Creakings can spawn even when the game rule doMobSpawning is set to false.