[ci skip] Fix multiple ItemStack array nullability mistakes (#7055)

Co-authored-by: Jake Potrebic <jake.m.potrebic@gmail.com>

patches/api/Fix-Spigot-annotation-mistakes.patch

@@ -105,6 +105,29 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
      @NotNull
      public int[] getExpLevelCostsOffered() {
          int[] levelOffers = new int[offers.length];
+diff --git a/src/main/java/org/bukkit/inventory/CraftingInventory.java b/src/main/java/org/bukkit/inventory/CraftingInventory.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/inventory/CraftingInventory.java
++++ b/src/main/java/org/bukkit/inventory/CraftingInventory.java
+@@ -0,0 +0,0 @@ public interface CraftingInventory extends Inventory {
+      *
+      * @return The contents. Individual entries may be null.
+      */
+-    @NotNull
+-    ItemStack[] getMatrix();
++    @Nullable ItemStack @NotNull [] getMatrix(); // Paper - make array elements nullable instead array
+ 
+     /**
+      * Set the item in the result slot of the crafting inventory.
+@@ -0,0 +0,0 @@ public interface CraftingInventory extends Inventory {
+      * @throws IllegalArgumentException if the length of contents is greater
+      *     than the size of the crafting matrix.
+      */
+-    void setMatrix(@NotNull ItemStack[] contents);
++    void setMatrix(@Nullable ItemStack @NotNull [] contents); // Paper - make array elements nullable instead array
+ 
+     /**
+      * Get the current recipe formed on the crafting inventory, if any.
 diff --git a/src/main/java/org/bukkit/inventory/Inventory.java b/src/main/java/org/bukkit/inventory/Inventory.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/inventory/Inventory.java
@@ -119,6 +142,34 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
  
      /**
       * Completely replaces the inventory's contents. Removes all existing
+@@ -0,0 +0,0 @@ public interface Inventory extends Iterable<ItemStack> {
+      * @throws IllegalArgumentException If the array has more items than the
+      *     inventory.
+      */
+-    public void setContents(@NotNull ItemStack[] items) throws IllegalArgumentException;
++    public void setContents(@Nullable ItemStack @NotNull [] items) throws IllegalArgumentException; // Paper - make array elements nullable instead array
+ 
+     /**
+      * Return the contents from the section of the inventory where items can
+@@ -0,0 +0,0 @@ public interface Inventory extends Iterable<ItemStack> {
+      *
+      * @return inventory storage contents. Individual items may be null.
+      */
+-    @NotNull
+-    public ItemStack[] getStorageContents();
++    public @Nullable ItemStack @NotNull [] getStorageContents(); // Paper - make array elements nullable instead array
+ 
+     /**
+      * Put the given ItemStacks into the storage slots
+@@ -0,0 +0,0 @@ public interface Inventory extends Iterable<ItemStack> {
+      * @throws IllegalArgumentException If the array has more items than the
+      * inventory.
+      */
+-    public void setStorageContents(@NotNull ItemStack[] items) throws IllegalArgumentException;
++    public void setStorageContents(@Nullable ItemStack @NotNull [] items) throws IllegalArgumentException; // Paper - make array elements nullable instead array
+ 
+     /**
+      * Checks if the inventory contains any ItemStacks with the given
 diff --git a/src/main/java/org/bukkit/inventory/ItemFactory.java b/src/main/java/org/bukkit/inventory/ItemFactory.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/inventory/ItemFactory.java
@@ -169,6 +220,30 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
      public ItemMeta getItemMeta() {
          return this.meta == null ? Bukkit.getItemFactory().getItemMeta(this.type) : this.meta.clone();
      }
+diff --git a/src/main/java/org/bukkit/inventory/PlayerInventory.java b/src/main/java/org/bukkit/inventory/PlayerInventory.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/inventory/PlayerInventory.java
++++ b/src/main/java/org/bukkit/inventory/PlayerInventory.java
+@@ -0,0 +0,0 @@ public interface PlayerInventory extends Inventory {
+      *
+      * @return All the ItemStacks from the armor slots. Individual items can be null.
+      */
+-    @NotNull
+-    public ItemStack[] getArmorContents();
++    public @Nullable ItemStack @NotNull [] getArmorContents(); // Paper - make array elements nullable instead array
+ 
+     /**
+      * Get all additional ItemStacks stored in this inventory.
+@@ -0,0 +0,0 @@ public interface PlayerInventory extends Inventory {
+      *
+      * @return All additional ItemStacks. Individual items can be null.
+      */
+-    @NotNull
+-    public ItemStack[] getExtraContents();
++    public @Nullable ItemStack @NotNull [] getExtraContents(); // Paper - make array elements nullable instead array
+ 
+     /**
+      * Return the ItemStack from the helmet slot
 diff --git a/src/main/java/org/bukkit/inventory/meta/ItemMeta.java b/src/main/java/org/bukkit/inventory/meta/ItemMeta.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/inventory/meta/ItemMeta.java