Adds sidekiq config to define logger level as WARN

[mattfeg]

Fix #258

• Context
  When running rspec we got the following output:

2025-04-05T11:53:47.468Z pid=90 tid=4ua INFO: Sidekiq 7.2.4 connecting to Redis with options {:size=>10, :pool_name=>"internal", :url=>"redis://redis:6379/0"}

• Solution
  "We log that line because connecting correctly to Redis is the number one support issue with Sidekiq. The user should see when Sidekiq tries to connect and the parameters it is using to connect."

On specs config, Define Sidekiq logger level as Warning.

sidekiq/sidekiq#6181