always flush chunk updates when tick freezes (#422)

src/main/java/carpet/fakes/ThreadedAnvilChunkStorageInterface.java

@@ -3,6 +3,7 @@ package carpet.fakes;
 import java.util.List;
 import java.util.Map;
 
+import net.minecraft.server.world.ChunkHolder;
 import net.minecraft.util.math.ChunkPos;
 
 public interface ThreadedAnvilChunkStorageInterface
@@ -12,4 +13,6 @@ public interface ThreadedAnvilChunkStorageInterface
     void relightChunk(ChunkPos pos);
 
     void releaseRelightTicket(ChunkPos pos);
+
+    Iterable<ChunkHolder> getChunks();
 }