Fly with nostalgia

Loader-specific changes:

• Fabric: fixed the mod jar not containing remapped methods

• Added permissions for /fly command as alternative to OP privileges
• Added Slovak translations

Loader-specific changes:

• Sponge: added permission descriptions

Updated to Minecraft 1.21.4

Release for Minecraft 1.21.1

• Sponge support
• Way more flexible command arguments handling
• Command blocks support

• NeoForge support
• Way more flexible command arguments handling
• Command blocks support

• Forge support
• Way more flexible command arguments handling
• Command blocks support

• Way more flexible command arguments handling
• Command blocks support

Review release for the Fabric loader