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/Expand-ArmorStand-API.patch

@@ -8,7 +8,7 @@ Add the following:
 - Enable/Disable slot interactions
 
 diff --git a/src/main/java/org/bukkit/entity/ArmorStand.java b/src/main/java/org/bukkit/entity/ArmorStand.java
-index 859f166f..eda4873d 100644
+index 492df420b..e7f71e65e 100644
 --- a/src/main/java/org/bukkit/entity/ArmorStand.java
 +++ b/src/main/java/org/bukkit/entity/ArmorStand.java
 @@ -0,0 +0,0 @@
@@ -17,7 +17,7 @@ index 859f166f..eda4873d 100644
 +import org.bukkit.inventory.EquipmentSlot;
  import org.bukkit.inventory.ItemStack;
  import org.bukkit.util.EulerAngle;
- 
+ import org.jetbrains.annotations.NotNull;
 @@ -0,0 +0,0 @@ public interface ArmorStand extends LivingEntity {
       * currently holding
       *
@@ -27,6 +27,7 @@ index 859f166f..eda4873d 100644
 +     * @see ArmorStand#getItem(EquipmentSlot)
 +     // Paper end
       */
+     @NotNull
 +    @Deprecated // Paper
      ItemStack getItemInHand();
  
@@ -41,7 +42,7 @@ index 859f166f..eda4873d 100644
 +     // Paper end
       */
 +    @Deprecated // Paper
-     void setItemInHand(ItemStack item);
+     void setItemInHand(@Nullable ItemStack item);
  
      /**
 @@ -0,0 +0,0 @@ public interface ArmorStand extends LivingEntity {
@@ -56,7 +57,8 @@ index 859f166f..eda4873d 100644
 +     * @param slot the equipment slot to get
 +     * @return the ItemStack in the equipment slot
 +     */
-+    ItemStack getItem(final org.bukkit.inventory.EquipmentSlot slot);
++    @NotNull
++    ItemStack getItem(@NotNull final org.bukkit.inventory.EquipmentSlot slot);
 +
 +    /**
 +     * Sets the item the armor stand has
@@ -65,13 +67,14 @@ index 859f166f..eda4873d 100644
 +     * @param slot the equipment slot to set
 +     * @param item the item to hold
 +     */
-+    void setItem(final org.bukkit.inventory.EquipmentSlot slot, final ItemStack item);
++    void setItem(@NotNull final org.bukkit.inventory.EquipmentSlot slot, @Nullable final ItemStack item);
 +
 +    /**
 +     * Get the list of disabled slots
 +     *
 +     * @return list of disabled slots
 +     */
++    @NotNull
 +    java.util.Set<org.bukkit.inventory.EquipmentSlot> getDisabledSlots();
 +
 +    /**
@@ -82,7 +85,7 @@ index 859f166f..eda4873d 100644
 +     *
 +     * @param slots var-arg array of slots to lock
 +     */
-+    void setDisabledSlots(org.bukkit.inventory.EquipmentSlot... slots);
++    void setDisabledSlots(@NotNull org.bukkit.inventory.EquipmentSlot... slots);
 +
 +    /**
 +     * Disable specific slots, adding them
@@ -93,7 +96,7 @@ index 859f166f..eda4873d 100644
 +     *
 +     * @param slots var-arg array of slots to lock
 +     */
-+    void addDisabledSlots(final org.bukkit.inventory.EquipmentSlot... slots);
++    void addDisabledSlots(@NotNull final org.bukkit.inventory.EquipmentSlot... slots);
 +
 +    /**
 +     * Remove the given slots from the disabled
@@ -103,7 +106,7 @@ index 859f166f..eda4873d 100644
 +     *
 +     * @param slots var-arg array of slots to unlock
 +     */
-+    void removeDisabledSlots(final org.bukkit.inventory.EquipmentSlot... slots);
++    void removeDisabledSlots(@NotNull final org.bukkit.inventory.EquipmentSlot... slots);
 +
 +    /**
 +     * Check if a specific slot is disabled
@@ -111,7 +114,7 @@ index 859f166f..eda4873d 100644
 +     * @param slot The slot to check
 +     * @return {@code true} if the slot is disabled, else {@code false}.
 +     */
-+    boolean isSlotDisabled(org.bukkit.inventory.EquipmentSlot slot);
++    boolean isSlotDisabled(@NotNull org.bukkit.inventory.EquipmentSlot slot);
      // Paper end
  }
 --