Update auto_duo_code_review_enabled setting to use new cascading worker

What does this MR do and why?

• This MR updates the existing auto_duo_code_review_enabled cascading settings to use sidekiq workers that were added in this MR: Adds sidekiq workers to cascade ai settings (!204464 - merged)
• auto_duo_code_review_enabled cascading setting was introduced in !201399 (merged) and !201832 (merged)
• Relevant discussion: !202745 (comment 2737935402)

How to set up and validate locally

Prerequisites:

• Make sure the AI features are enabled locally using this guide
• Use http://localhost:3000/gitlab-duo group which already has Duo Enterprise add-on and duo_features_enabled: true
• Enable feature flag in Rails console: Feature.enable(:cascading_auto_duo_code_review_settings)

Validate group level:

• As group owner, go to Settings > General > Merge requests → GitLab Duo Code Review and enable the setting
• Create a subgroup/project → Go to subgroup (or project)'s settings → Auto review checkbox should be enabled and editable (inherited but can be changed). Disable and enable again.
• Go back to the group and disable GitLab Duo Code Review and verify that the subgroup/project level settings also get disabled

Validate instance level:

• As admin, go to Admin Area > Settings > General → GitLab Duo Code Review and enable the setting
• Create a group/project → Go to group (or project)'s settings → Auto review checkbox should be enabled and editable (inherited but can be changed). Disable and enable again.
• Go back to the admin setting and disable GitLab Duo Code Review and verify that the subgroup/project level settings also get disabled

MR acceptance checklist

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