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/Add-getTPS-method.patch

@@ -5,7 +5,7 @@ Subject: [PATCH] Add getTPS method
 
 
 diff --git a/src/main/java/org/bukkit/Bukkit.java b/src/main/java/org/bukkit/Bukkit.java
-index 14e425d1..6055c801 100644
+index cffa0c65f..2ad9a7d7f 100644
 --- a/src/main/java/org/bukkit/Bukkit.java
 +++ b/src/main/java/org/bukkit/Bukkit.java
 @@ -0,0 +0,0 @@ public final class Bukkit {
@@ -17,6 +17,7 @@ index 14e425d1..6055c801 100644
 +     * Gets the current server TPS
 +     * @return current server TPS (1m, 5m, 15m in Paper-Server)
 +     */
++    @NotNull
 +    public static double[] getTPS() {
 +        return server.getTPS();
 +    }
@@ -26,12 +27,12 @@ index 14e425d1..6055c801 100644
       * Get the advancement specified by this key.
       *
 diff --git a/src/main/java/org/bukkit/Server.java b/src/main/java/org/bukkit/Server.java
-index 9d2326ca..1632af18 100644
+index 9f7f760af..3ad70b92f 100644
 --- a/src/main/java/org/bukkit/Server.java
 +++ b/src/main/java/org/bukkit/Server.java
 @@ -0,0 +0,0 @@ public interface Server extends PluginMessageRecipient {
-      */
-     Entity getEntity(UUID uuid);
+     @Nullable
+     Entity getEntity(@NotNull UUID uuid);
  
 +    // Paper start
 +    /**
@@ -39,6 +40,7 @@ index 9d2326ca..1632af18 100644
 +     *
 +     * @return current server TPS (1m, 5m, 15m in Paper-Server)
 +     */
++    @NotNull
 +    public double[] getTPS();
 +    // Paper end
 +