[TECH DEBT] `redis-py-cluster` is unmaintained and unnecessary

[lkubb]

Description of the tech debt to be addressed, include links and screenshots

Redis cluster support in these modules is provided by https://github.com/grokzen/redis-py-cluster, which wraps redis-py. The functionality has been merged into redis-py in 2021 (v4.1.0) and redis-py-cluster was archived after.

We should port the modules to use redis-py directly for cluster mode support. This should be pretty easy.

This came up during debugging of #18