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
CraftBukkit Changes:
983305bb SPIGOT-5856: Soul Campfire BlockState cannot be cast to Campfire
This also cleans up the implementation of Async Chunks to get rid of most
Consumer callbacks and instead return futures.
This lets us propogate errors correctly up the future chain
(barring one isn't lost even deeper in the chain...)
So exceptions can now bubble to plugins using getChunkAtAsync