Don't delay chunk unloads during entity ticking

Leaf informed me this could cause ordering issues.

So, the risk if this occurring is lowered now anyways, but if an
entity causes a sync chunk load, it could process an unload...

We will tackle the problem better in a future commit

Also fixed another async-chunks=false issue

Spigot-Server-Patches/Asynchronous-chunk-IO-and-loading.patch

@@ -1902,7 +1902,7 @@ index 0000000000..1dfa8abfd8
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/io/chunk/ChunkTaskManager.java b/src/main/java/com/destroystokyo/paper/io/chunk/ChunkTaskManager.java
 new file mode 100644
-index 0000000000..ff19d38f82
+index 0000000000..0745a2015a
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/io/chunk/ChunkTaskManager.java
 @@ -0,0 +0,0 @@
@@ -2297,7 +2297,7 @@ index 0000000000..ff19d38f82
 +                worker.flush();
 +            }
 +        }
-+        globalUrgentWorker.flush();
++        if (globalUrgentWorker != null) globalUrgentWorker.flush();
 +
 +        // flush again since tasks we execute async saves
 +        drainChunkWaitQueue();

Spigot-Server-Patches/Delay-unsafe-actions-until-after-entity-ticking-is-d.patch

@@ -5,22 +5,6 @@ Subject: [PATCH] Delay unsafe actions until after entity ticking is done
 
 This will help prevent many cases of unregistering entities during entity ticking
 
-diff --git a/src/main/java/net/minecraft/server/PlayerChunk.java b/src/main/java/net/minecraft/server/PlayerChunk.java
-index a9a2ce3d3f..24cb88559b 100644
---- a/src/main/java/net/minecraft/server/PlayerChunk.java
-+++ b/src/main/java/net/minecraft/server/PlayerChunk.java
-@@ -0,0 +0,0 @@ public class PlayerChunk {
-                         // Minecraft will apply the chunks tick lists to the world once the chunk got loaded, and then store the tick
-                         // lists again inside the chunk once the chunk becomes inaccessible and set the chunk's needsSaving flag.
-                         // These actions may however happen deferred, so we manually set the needsSaving flag already here.
-+                        // Paper start
-+                        ((WorldServer) chunk.world).doIfNotEntityTicking(() -> { // Paper
-                         chunk.setNeedsSaving(true);
-                         chunk.unloadCallback();
-+                        }); // Paper
-                     });
-                 }
-             }).exceptionally((throwable) -> {
 diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
 index cd8266f675..84a3367b87 100644
 --- a/src/main/java/net/minecraft/server/WorldServer.java