ConcurrentModificationException when breaking linked relay

[Robotgiggle]

Minecraft version

1.20.1

Hex Casting version

0.11.3

Hexal version

0.3.1

Issue description

Sometimes, when breaking a relay that is linked to other relays, the BlockEntityRelay.disconnectAll method throws a ConcurrentModificationException as shown below:

[19:00:11] [Server thread/ERROR]: Failed to handle packet net.minecraft.class_2846@74dfea74, suppressing error
java.util.ConcurrentModificationException: null
	at java.util.LinkedHashMap$LinkedHashIterator.nextNode(LinkedHashMap.java:756) ~[?:?]
	at java.util.LinkedHashMap$LinkedKeyIterator.next(LinkedHashMap.java:778) ~[?:?]
	at ram.talia.hexal.common.blocks.entity.BlockEntityRelay.disconnectAll(BlockEntityRelay.kt:230) ~[hexal-fabric-1.20.1-0.3.1.jar:?]

This is particularly unusual as disconnectAll loops over and modifies a MutableSet, the documentation for which explicitly states that modifying the set mid-iteration is allowed.

Steps to reproduce

• Place down some relays
• Link them together
• Break a relay that is connected to multiple other relays
• Observe error in log