[WIP] Update to 1.21.6

[Onako2]

Update to 1.21.6.

TODO:

• [x] Get it to run
• [ ] Update mobs.png (add happy ghast)
• [ ] Find out the tool tip location
  • Current temp. solution against crash: null it
• [ ] Fix rendering of entity preview screen
  • [ ] Fix Entity Preview
    • [x] Make it partially but still broken render
    • [ ] Make it fully render without any issues (problem is that it can currently render one entity at a time)
    • [ ] Make it moveable (seat)
  • [x] Fix buttons in preview screen
• [ ] Happy Ghast
  • [x] Add to config
  • [ ] Test if it works ingame because I am worried about it breaking because it has multiple passengers
• [x] Remove share to LAN stuff I added quick and dirty when Fabric API and ModMenu wasn't and maybe still isn't working so I could test it out. Remove when Mod Menu has an update