Create Structures Overhaul fix

The malformed nether_forpost loot table is overridden by:
kubejs/data/create_structures_overhaul/loot_table/nether_forpost.json

This remains inside the main KubeJS folder. No separate datapack is required.
The former LootJS script was removed because LootJS cannot modify a loot table
that failed to load and therefore does not exist.
