Modules: RedisModuleCallback not handling blocked clients

[Dudemullet]

Problem

Lets say we have a registered callback on keyspace events via a the modules api. This callback adds messages to list whenever a key expires.

Now on the client side we run the following commands

SET myKey value EX 10
> OK
BLPOP list 0

Expected

The expectation is that when myKey expires, the RedisModuleCallback will add a message to list. The blocked client should pop that message from list.

Ocurring

The client never gets handled and remains blocked, even though a message has been added to list

[Dudemullet]

This behavior is still present in branch 6.0