Fix incorrect annotation on BrushableBlock#getItem (#9345)

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

@@ -331,6 +331,19 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +    @Deprecated // Paper
      void setData(@NotNull MaterialData data);
  
+     /**
+diff --git a/src/main/java/org/bukkit/block/BrushableBlock.java b/src/main/java/org/bukkit/block/BrushableBlock.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/block/BrushableBlock.java
++++ b/src/main/java/org/bukkit/block/BrushableBlock.java
+@@ -0,0 +0,0 @@ public interface BrushableBlock extends Lootable, TileState {
+      *
+      * @return the item
+      */
+-    @Nullable
++    @org.jetbrains.annotations.NotNull // Paper
+     public ItemStack getItem();
+ 
      /**
 diff --git a/src/main/java/org/bukkit/block/DecoratedPot.java b/src/main/java/org/bukkit/block/DecoratedPot.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644