update dependencies

[FireInstall]

Updated the dependencies to the newest (1.20.6) version. Most importantly is OpenInv with a change in its public API, where "retainPlayer" is now marked for removal.

I know the way I aggressively pushed everything to the newest versions probably means loading this version on older Spigot/Paper versions doesn't work, but since there is version indifferent reflection, loading it in the api defined 1.13 could have been broken anyway.