Prefab roots should not be deactivated by Nautilus

[LeeTwentyThree]

Changes made in this pull request

• Removed an unnecessary SetActive(false) call that affected all prefabs during their construction.
  • This caused "real prefabs" to stay deactivated, which led to unintentional behavior (such as stopping buildables from working entirely).

Breaking changes

• Uncached prefabs that live in the scene ("fake prefabs") may now need to be manually disabled by modders. Otherwise, they will remain active within the world.
  • This change will likely not affect any existing mods. Uncached prefabs are meant for advanced use cases only.