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-LivingEntity-getTargetEntity.patch

@@ -6,7 +6,7 @@ Subject: [PATCH] Add LivingEntity#getTargetEntity
 
 diff --git a/src/main/java/com/destroystokyo/paper/entity/TargetEntityInfo.java b/src/main/java/com/destroystokyo/paper/entity/TargetEntityInfo.java
 new file mode 100644
-index 00000000..5df8eed2
+index 000000000..f52644fab
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/entity/TargetEntityInfo.java
 @@ -0,0 +0,0 @@
@@ -14,6 +14,7 @@ index 00000000..5df8eed2
 +
 +import org.bukkit.entity.Entity;
 +import org.bukkit.util.Vector;
++import org.jetbrains.annotations.NotNull;
 +
 +/**
 + * Represents information about a targeted entity
@@ -22,7 +23,7 @@ index 00000000..5df8eed2
 +    private final Entity entity;
 +    private final Vector hitVec;
 +
-+    public TargetEntityInfo(Entity entity, Vector hitVec) {
++    public TargetEntityInfo(@NotNull Entity entity, @NotNull Vector hitVec) {
 +        this.entity = entity;
 +        this.hitVec = hitVec;
 +    }
@@ -32,6 +33,7 @@ index 00000000..5df8eed2
 +     *
 +     * @return Targeted entity
 +     */
++    @NotNull
 +    public Entity getEntity() {
 +        return entity;
 +    }
@@ -41,18 +43,19 @@ index 00000000..5df8eed2
 +     *
 +     * @return Targeted position
 +     */
++    @NotNull
 +    public Vector getHitVector() {
 +        return hitVec;
 +    }
 +}
 diff --git a/src/main/java/org/bukkit/entity/LivingEntity.java b/src/main/java/org/bukkit/entity/LivingEntity.java
-index bd47e720..34a8fe3f 100644
+index 4dec50caf..956d68867 100644
 --- a/src/main/java/org/bukkit/entity/LivingEntity.java
 +++ b/src/main/java/org/bukkit/entity/LivingEntity.java
 @@ -0,0 +0,0 @@ public interface LivingEntity extends Attributable, Damageable, ProjectileSource
       */
      @Nullable
-     public com.destroystokyo.paper.block.TargetBlockInfo getTargetBlockInfo(int maxDistance, com.destroystokyo.paper.block.TargetBlockInfo.FluidMode fluidMode);
+     public com.destroystokyo.paper.block.TargetBlockInfo getTargetBlockInfo(int maxDistance, @NotNull com.destroystokyo.paper.block.TargetBlockInfo.FluidMode fluidMode);
 +
 +    /**
 +     * Gets information about the entity being targeted