Squads sometimes fail to delete Marines references, bricking OW Console

[fira]

Testmerges

#4475, #4812, #4793, #4866, #4879, #4889

Round ID

19491, more

Description of the bug

Observed two times. In both cases the SL for the squad was deleted.
This causes the OW console to crash due to trying to get dist between marines and SL while it is in nullspace.

First case the console only briefly crashed before recovering.
During Round 19491 however the references to the SL (Spec assigned SL) were never cleared and it remained broken.

What's the difference with what should have happened?

The squad datum should automatically clear references to deleted squad members using the signal hooked in put_marine_in_squad

How do we reproduce this bug?

Unknown

This could be fixed by fixing the Z check in OW console, but arguably fixing the root cause would be much better

Issue Bingo

• Issue could be reproduced at least once
• Issue happened in a recent (less than 7 days ago) round
• Couldn't find an existing issue about this (https://github.com/cmss13-devs/cmss13/issues)