Prevent hoppers from being sucked by other hoppers

[Distolfix]

Summary

Fixed a critical bug where hoppers would vacuum other dropped hopper items, causing item loss when breaking multiple hoppers quickly.

Changes

• Added a check in ModuleSuction.java to exclude Material.HOPPER from suction
• Hoppers dropped as items will no longer be picked up by other hoppers with suction enabled
• Players must manually collect dropped hoppers

Why this fix

When breaking multiple hoppers quickly in proximity:

1. Hopper A breaks and drops as an item entity
2. Hopper B (with suction) would immediately vacuum the dropped hopper
3. If Hopper B was then broken quickly, items could be lost due to race conditions with the cache/transfer system

By preventing hoppers from vacuuming other hoppers, the items remain on the ground safely for manual collection.

Testing

Tested with 10+ level 4 hoppers with suction enabled, breaking them rapidly - all hoppers are now properly preserved as ground items.