Do not throttle when sync dev env var set

What does this MR do and why?

When PM_SYNC_IN_DEV env variable is set, it is being run locally and throttling the package metadata sync is undesirable because it is almost always an initial sync and done on a powerful enough machine.

This MR removes the throttling in that case.

How to set up and validate locally

Follow the instructions to set up sync here: gitlab-development-kit!3469 (comment 1672102863)

Run sync in the main branch and tail -f log/application_json.log to see how quickly the Evaluating ... entries come up.

Run sync in this branch and see the entries processed much faster.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.