Elementals 1.48.6 GeckoLib Forge 4.8.4 Connector Compat - No NBT Sync Fix

This build keeps:
- GeckoLib Forge 4.8.4 renderer compatibility fix for Elementals armor/glider items
- Java 17 compatibility
- Prior null-safe saved data patch

New multiplayer safety change:
- Disables Elementals upgrade-list NBT network sync packets:
  * dev.saperate.elementals.packets.SyncUpgradeListS2CPacket
  * dev.saperate.elementals.network.packets.GetUpgradeListC2SPacket

Why:
- Through Sinytra Connector, Elementals' upgrade-list packet can produce/receive a null CompoundTag.
- That disconnects players with an "NBT data is null" / CompoundTag null message.
- This build avoids sending or reading that fragile NBT payload at all.

Expected tradeoff:
- Elementals should load and let players join.
- The upgrade tree's synced purchased/toggled upgrade display may not update correctly in multiplayer.
- Core bending/chi/level sync remains untouched.

Install on BOTH server and every client. Delete all older Elementals compat, bridge, and elementals_reborn test jars.
