Fix unleash reason

Author: Harry Bridgen

paper-server/patches/sources/net/minecraft/world/entity/Leashable.java.patch

@@ -40,7 +40,7 @@
 +                // Paper start - Expand EntityUnleashEvent
 +                final org.bukkit.event.entity.EntityUnleashEvent event = new org.bukkit.event.entity.EntityUnleashEvent(
 +                    entity.getBukkitEntity(),
-+                    !entity.isAlive() ? org.bukkit.event.entity.EntityUnleashEvent.UnleashReason.PLAYER_UNLEASH : org.bukkit.event.entity.EntityUnleashEvent.UnleashReason.HOLDER_GONE,
++                    !entity.isAlive() ? org.bukkit.event.entity.EntityUnleashEvent.UnleashReason.LEASHED_GONE : org.bukkit.event.entity.EntityUnleashEvent.UnleashReason.HOLDER_GONE,
 +                    level.getGameRules().get(GameRules.ENTITY_DROPS) && !entity.pluginRemoved
 +                );
 +                event.callEvent();