BootstrapContext registry lookup is not available for data gen registries

[Cheaterpaul]

Minecraft Version: 1.20.1

Forge Version: 47.1.0

Logs: https://gist.github.com/Cheaterpaul/20db541611824a6340bc40e631aba80c

Steps to Reproduce:

1. call BootstapContext#registryLookup with a world gen registry eg. Registries.BIOME
2. run the forge test data generation

Description of issue:
#9225 added the BootstapContext#registryLookup method and wrapped the registry lookup so it can be actually used. The problem here is that the datagen registries are using the UniversalLookup instead of a RegistryLookup. This causes BootstrapContext#registryLookup to fail as ClassCastException.

This can be reproduced in the forge dev environment by adding context.registryLookup(Registries.BIOME) in the BiomeModifierTest#BUILDER