Rebalance conductor trades

[OpenBagTwo]

No concrete action item yet, but tracking the changes introduced in 23w31a suggests that conductors in 1.20.2 should have biome-specific tradelists.

A singular guaranteed max-level disc won't work since that would require the number of discs be tied to the number of villager types (though maybe this could be set in the config?), but it would be simple enough to make the trade pools biome-specific via modulo arithmetic (similar to how the comparator signal strength reading works).

Anyway, as of Aug 3 the plan is just to wait and see what happens in subsequent snapshots, but once we see how this looks for a few more villagers, I think we can start rolling out some experimental changes.