Update to 1.16.5 (also update gradle and loom and run gradlew wrapper)

[Fourmisain]

Fixes boot crash due to the outdated SignEditScreenMixin mixin (https://github.com/Ivan0xFF/BetterSignsAndFrames/issues/4).

The mixin was completely removed since it isn't needed anymore, at least I cannot reproduce https://github.com/Ivan0xFF/BetterSignsAndFrames/issues/2 in 1.16.5.

These features work server-only:

• Placing signs without opening the edit dialog
• Editing signs via shift-rightclick
• Passthrough signs on chests

This feature requires client installation:

• Passthrough itemframes on chests (and https://github.com/Ivan0xFF/BetterSignsAndFrames/issues/3 is still an issue)

[craftycorvid]

Hey, I really appreciate you submitting this MR. I haven't been playing Minecraft, and just haven't found the time to update the plugin. I'll review it and get it up to curseforge ASAP.

[craftycorvid]

Looks great! Thanks again!