Don't allow for supporting block checks to load chunks

I cannot test this due to lack of hardware (took 30 minutes getting paper
updated and loaded into IJ on this machine...), however, this is the easiest
patch for now. Ideally, some form of distance check would probably be added to
improve invalidation of this cache.

patches/server/0019-Rewrite-chunk-system.patch

@@ -21199,7 +21199,7 @@ index d87f02c748fe2e5b4ea251f6691e8907a152cb6d..5988c0847af4e8f0094328e91f736f25
 +    // Paper end
  }
 diff --git a/src/main/java/net/minecraft/world/level/LevelReader.java b/src/main/java/net/minecraft/world/level/LevelReader.java
-index fe76ec5b10242beb6d6057bd680484fc63b7eac3..e3e2b88b8ade4fa2b482626c7e00ac6a0bf8eb5e 100644
+index cc0d20e9f851268fe8403ac516f426ec1d008150..12eaafdbd324fa36b3f46c3b644bc8117a4123ad 100644
 --- a/src/main/java/net/minecraft/world/level/LevelReader.java
 +++ b/src/main/java/net/minecraft/world/level/LevelReader.java
 @@ -26,6 +26,15 @@ public interface LevelReader extends BlockAndTintGetter, CollisionGetter, Signal
@@ -21216,8 +21216,8 @@ index fe76ec5b10242beb6d6057bd680484fc63b7eac3..e3e2b88b8ade4fa2b482626c7e00ac6a
 +    // Paper end - rewrite chunk system
 +
      @Nullable ChunkAccess getChunkIfLoadedImmediately(int x, int z); // Paper - ifLoaded api (we need this since current impl blocks if the chunk is loading)
+     @Nullable default ChunkAccess getChunkIfLoadedImmediately(BlockPos pos) { return this.getChunkIfLoadedImmediately(pos.getX() >> 4, pos.getZ() >> 4);}
  
-     /** @deprecated */
 diff --git a/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java b/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
 index f739a175e26f250c652c73b8985158fe37c2823a..5f4fa76fe3a1a0a4fc11064fcf57bfab20bd9729 100644
 --- a/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java