Perform AI completion Sidekiq jobs inline when on dev environment

What does this MR do and why?

Duo Chat can appear to lag often in local development due to hanging Sidekiq jobs.

There has been a trick known about how to get around this, but many devs do not realize the trick and end up frustrated when trying to develop for Duo Chat.

This change causes the completion jobs to run synchronously on the development environment automatically.

MR acceptance checklist

✅

Screenshots or screen recordings

N/A

How to set up and validate locally

N/A