[#485] Fix concurrency crashes in chunk obfuscation and proximity checks

[Ingrim4]

Description

This PR fixes several concurrency and stability issues related to chunk obfuscation, proximity checks, and diagnostics.

Fixes

• Fixed ConcurrentModificationException in PlayerAccessorManager and WorldAccessorManager.
• Fixed ConcurrentModificationException in WrappedClientboundLevelChunkPacketData.
• Fixed CI cache configuration for Minecraft 1.21.11.
• Fixed ProximitySystem crashes caused by errors not being caught correctly.
• Scheduled players for a proximity check when their current chunk was obfuscated.

Added

• Added thread and executor information to dump files to improve debugging.

Related Issue

closes #485

How Has This Been Tested?

Tested with the latest version for spigot/paper.

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)