the PreventJockeyMounts option doesn't work

Summary the option is not working

Steps to reproduce

1. Use the mob in this pastebin: https://pastebin.com/4g6jPebJ
2. Spawn A LOT of them

NOTE: spawning something like 300-500 zombies will most likely spawn a chicken but the chicken will instantly die due to extreme aviary compression with zombies. Still, you will see the corpse of the animal on the ground (raw chickens or feathers)

Current behavior You can check in this video: https://youtu.be/H0mi5PStBrk

I was very lucky because a chicken spawned kinda quickly, you will probably need to spawn a lot more (500 minimum should guarantee a chicken)

Intended correct behavior It should not spawn zombies mounting chickens

Server log file https://pastebin.com/CLD2EMeQ

Debug log snippet https://pastebin.com/RT9rt6Cd