Updated Upstream (Bukkit/CraftBukkit/Spigot)

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

Please note that this build includes changes to meet upstreams
requirements for nullability annotations. While we aim for a level of
accuracy, these might not be 100% correct, if there are any issues,
please speak to us on discord, or open an issue on the tracker to
discuss.

Bukkit Changes:
9a6a1de3 Remove nullability annotations from enum constructors
3f0591ea SPIGOT-2540: Add nullability annotations to entire Bukkit API

CraftBukkit Changes:
8d8475fc SPIGOT-4666: Force parameter in HumanEntity#sleep
8b1588e2 Fix ExplosionPrimeEvent#setFire not working with EnderCrystals
39a287b7 Don't ignore newlines in PlayerListHeader/Footer

Spigot Changes:
cf694d87 Add nullability annotations

Spigot-API-Patches/0117-Add-World.getEntity-UUID-API.patch

@@ -1,30 +0,0 @@
-From 0ca84ee15c94cc1a2849f7c9476c58c127283221 Mon Sep 17 00:00:00 2001
-From: Brokkonaut <hannos17@gmx.de>
-Date: Tue, 3 Jul 2018 16:07:16 +0200
-Subject: [PATCH] Add World.getEntity(UUID) API
-
-
-diff --git a/src/main/java/org/bukkit/World.java b/src/main/java/org/bukkit/World.java
-index c73b7065..e424ed4e 100644
---- a/src/main/java/org/bukkit/World.java
-+++ b/src/main/java/org/bukkit/World.java
-@@ -741,6 +741,16 @@ public interface World extends PluginMessageRecipient, Metadatable {
-      */
-     public Collection<Entity> getNearbyEntities(Location location, double x, double y, double z);
- 
-+    // Paper start - getEntity by UUID API
-+    /**
-+     * Gets an entity in this world by its UUID
-+     *
-+     * @param uuid the UUID of the entity
-+     * @return the entity with the given UUID, or null if it isn't found
-+     */
-+    public Entity getEntity(UUID uuid);
-+    // Paper end
-+
-     /**
-      * Returns a list of entities within a bounding box centered around a
-      * Location.
--- 
-2.20.1
-