Blocking pops block the connection when the origin already has enough items

[prvyk]

Describe the bug

Example:

ZADD a 1 one
ZADD a 2 two
ZADD b 3 three
BZMPOP 0 2 a b MIN COUNT 2
-> redis-cli never returns.

The order in InitializeObserver() is likely wrong (what if a key is inserted after the loop checking it but before its observer being set up?), but that's not the cause here. The lock is actually freed?

This discussion may be related:
#1046

Steps to reproduce the bug

ZADD a 1 one
ZADD a 2 two
ZADD b 3 three
BZMPOP 0 2 a b MIN COUNT 2

Expected behavior

1. "a"
2. 1. 1. "one"
      2. "1"
   2. 1. "two"
      2. "2"

Screenshots

No response

Release version

v1.0.57

IDE

No response

OS version

No response

Additional context

No response