Allow controlling trace injection behaviour in queue gems

[sl0thentr0py]

@Linuus doing this in the clockwork process only should work as a workaround if you need it urgently.

Sidekiq.configure_client do |config|
  config.client_middleware do |chain|
    chain.remove Sentry::Sidekiq::SentryContextClientMiddleware
  end
end

This will remove the trace header injection but only in the clockwork process. Make sure you don't put it in a general configuration.

For the longer term, I think I will add a configuration parameter to the sidekiq gem which lets you control the trace header injection behaviour.

Originally posted by @sl0thentr0py in #2391

[cobyeastwood183]

https://sentry.zendesk.com/agent/tickets/163096