Replacement Sidekiq error_handler logging at a different level

[randypuro]

Which for us, causes more noise as errors are already logged.

RailsSemanticLogger::Sidekiq::Defaults::ERROR_HANDLER logs at level warn:
https://github.com/reidmorrison/rails_semantic_logger/blob/master/lib/rails_semantic_logger/sidekiq/defaults.rb#L22

Whereas the original default ::Sidekiq::Config::ERROR_HANDLER logs at level log:
https://github.com/sidekiq/sidekiq/blob/main/lib/sidekiq/config.rb#L57