HolderOwners being wrapped messing up RegistryFixedCodec

[ZestyBlaze]

Minecraft Version: 1.21.3

NeoForge Version: 21.3.4-beta

Logs: https://mystb.in/b439b04c0f19ac9874

Steps to Reproduce:

1. Clone my mod locally
2. Trying doing runData task, experience crash

Description of issue:
This is being opened just as we try figure out what's going on but it's potentially an issue due to the way Neoforge wraps HolderOwner.
After a lot of discussion here, we came to a soft conclusion that everything in the code looks "right" and as it should. The Datapack Registry exists, and my Datamaps run okay until I try referring it to a RegistryFixedCodec instead of a direct codec, this is where the game starts crashing on running data now.
Commoble then suggested here that maybe due to Neoforge wrapping holderowners, it could be causing it to fail to serialise in a RegistryFixedCodec due to it becoming false, causing the error potentially.
Wanted to pop this up because if it is a bug with NF, it's halted my mod's progression for the mean time and I can't go any further with it just yet until a solution is found XD

[neoforged-releases]

🚀 This issue has been resolved in NeoForge version 21.3.6-beta, as part of #1648.