Fix NPE in processTrackQueue when chunk data is null

[UnlimitedBytes]

Fixes the following crash:

---- Minecraft Crash Report ----
// Oops.
// 
// DO NOT REPORT THIS TO PAPER! REPORT TO SHREDDEDPAPER INSTEAD!
// 

Time: 2026-01-09 01:30:31
Description: Exception in server tick loop

java.util.concurrent.CompletionException: java.lang.NullPointerException: Cannot read field "nearbyPlayers" because the return value of "ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity.moonrise$getChunkData()" is null
	at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:315)
	at java.base/java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:320)
	at java.base/java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1807)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
	at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: java.lang.NullPointerException: Cannot read field "nearbyPlayers" because the return value of "ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity.moonrise$getChunkData()" is null
	at io.multipaper.shreddedpaper.threading.ShreddedPaperEntityTicker.processTrackQueue(ShreddedPaperEntityTicker.java:44)
	at java.base/java.lang.Iterable.forEach(Iterable.java:75)
	at io.multipaper.shreddedpaper.threading.ShreddedPaperChunkTicker.lambda$processTrackQueueInParallel$6(ShreddedPaperChunkTicker.java:71)
	at java.base/java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1804)
	... 3 more

[PureGero]

How did you create this crash? This means something is removing the entity at the same time ShreddedPaperEntityTicker.processTrackQueue is called. I think there is a root cause that needs to be addressed instead of simply adding a null check

[UnlimitedBytes]

This was a crash that occurred during massive amount of player/bot testing with 2500 players/bots on the server. I will downgrade my local version to current build and try to trigger it again and send a follow up of latest.log & crash report if I can reproduce it.