AdventureZ Netherite Tweaks

The AdventureZ mod adds a few new sources of netherite, most of which are fairly balanced. 

The ender warthogs are a little problematic though - they make netherite extremely easy to farm once you reach The End, completely negating a large part of end game progression in many other mods.
This is made especially worse by mods that add power scaling, looting bonuses, and recipes that increase netherite yield. 

This is a simple balancing datapack that:
- Doubles the cost of the combine recipe (2 shells = 1 scrap -> 4 shells = 1 scrap)
- Makes Warthog Shell Pieces drop a bit less often

To use, add to your world's datapacks folder or use a datapack loader like Paxi