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:
a339310c #755: Fix NPE when calling getInventory() for virtual EnderChests
2577f9bf Increase outdated build delay
1dabfdc8 #754: Fix pre-1.16 serialized SkullMeta being broken on 1.16+, losing textures
