[ci skip] Drop "Fix CME on adding a passenger in CreatureSpawnEvent" (#6384)

This is no longer needed as Entity#passengers is an ImmutableList as of 1.17

patches/server/Fix-CME-on-adding-a-passenger-in-CreatureSpawnEvent.patch

@@ -1,19 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Jason Penilla <11360596+jpenilla@users.noreply.github.com>
-Date: Sun, 4 Oct 2020 19:55:25 -0700
-Subject: [PATCH] Fix CME on adding a passenger in CreatureSpawnEvent
-
-
-diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
---- a/src/main/java/net/minecraft/world/entity/Entity.java
-+++ b/src/main/java/net/minecraft/world/entity/Entity.java
-@@ -0,0 +0,0 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, n
-     }
- 
-     private Stream<Entity> getIndirectPassengersStream() {
--        return this.passengers.stream().flatMap(Entity::getSelfAndPassengers);
-+        return ImmutableList.copyOf(this.passengers).stream().flatMap(Entity::getSelfAndPassengers); // Paper
-     }
- 
-     @Override

patches/server/Optimize-indirect-passenger-iteration.patch

@@ -13,7 +13,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
  
      private Stream<Entity> getIndirectPassengersStream() {
 +        if (this.passengers.isEmpty()) { return Stream.of(); } // Paper
-         return ImmutableList.copyOf(this.passengers).stream().flatMap(Entity::getSelfAndPassengers); // Paper
+         return this.passengers.stream().flatMap(Entity::getSelfAndPassengers);
      }
  
      @Override