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/Expose-WorldBorder-isInBounds-Location-check.patch

@@ -5,13 +5,13 @@ Subject: [PATCH] Expose WorldBorder#isInBounds(Location) check
 
 
 diff --git a/src/main/java/org/bukkit/WorldBorder.java b/src/main/java/org/bukkit/WorldBorder.java
-index 4dc18edc..41b7fae6 100644
+index 7e8f5649..afb7b136 100644
 --- a/src/main/java/org/bukkit/WorldBorder.java
 +++ b/src/main/java/org/bukkit/WorldBorder.java
 @@ -0,0 +0,0 @@ public interface WorldBorder {
       * @return if this location is inside the border or not
       */
-     public boolean isInside(Location location);
+     public boolean isInside(@NotNull Location location);
 +
 +    // Paper start
 +    /**
@@ -22,7 +22,7 @@ index 4dc18edc..41b7fae6 100644
 +     * @deprecated use {@link #isInside(Location)} for an upstream compatible replacement
 +     */
 +    @Deprecated
-+    public default boolean isInBounds(Location location) {
++    public default boolean isInBounds(@NotNull Location location) {
 +        return this.isInside(location);
 +    }
 +    // Paper end