Fix null item in sendEquipmentChange (#9869)

patches/server/Allow-null-itemstack-for-Player-sendEquipmentChange.patch

@@ -0,0 +1,19 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: David Scandurra <david.scandurra@check24.de>
+Date: Wed, 25 Oct 2023 20:36:25 +0200
+Subject: [PATCH] Allow null itemstack for Player#sendEquipmentChange
+
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
++++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+@@ -0,0 +0,0 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
+ 
+     @Override
+     public void sendEquipmentChange(LivingEntity entity, EquipmentSlot slot, ItemStack item) {
+-        this.sendEquipmentChange(entity, Map.of(slot, item));
++        this.sendEquipmentChange(entity, java.util.Collections.singletonMap(slot, item)); // Paper - replace Map.of to allow null values
+     }
+ 
+     @Override