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/0005-Player-affects-spawning-API.patch

@@ -1,15 +1,15 @@
-From 44c7da0daea1759a7b45d8e5393ca84216ed9c0a Mon Sep 17 00:00:00 2001
+From 3fbe48f546b9da11b1e6baa07d639960dd30a9dc Mon Sep 17 00:00:00 2001
 From: Jedediah Smith <jedediah@silencegreys.com>
 Date: Mon, 29 Feb 2016 17:22:34 -0600
 Subject: [PATCH] Player affects spawning API
 
 
 diff --git a/src/main/java/org/bukkit/entity/Player.java b/src/main/java/org/bukkit/entity/Player.java
-index 75f21146..694254f1 100644
+index 777994f7..95ebf016 100644
 --- a/src/main/java/org/bukkit/entity/Player.java
 +++ b/src/main/java/org/bukkit/entity/Player.java
-@@ -1444,6 +1444,22 @@ public interface Player extends HumanEntity, Conversable, OfflinePlayer, PluginM
-      */
+@@ -1456,6 +1456,22 @@ public interface Player extends HumanEntity, Conversable, OfflinePlayer, PluginM
+     @NotNull
      public String getLocale();
  
 +    // Paper start
@@ -32,5 +32,5 @@ index 75f21146..694254f1 100644
       * Update the list of commands sent to the client.
       * <br>
 -- 
-2.20.1
+2.21.0