Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing
Bukkit Changes:
6875ad8b Update documentation and status of command completion related events
Let plugins be able to control tab completion of commands and chat async.
This will be useful for frameworks like ACF so we can define async safe completion handlers,
and avoid going to main for tab completions.
Especially useful if you need to query a database in order to obtain the results for tab
completion, such as offline players.
Also adds isCommand and getLocation to the sync TabCompleteEvent
