Add tmp indexes for CI partitioning - 3

Ref: #387301 (closed)

What does this MR do and why?

This MR adds temporary indexes to clean up efficiently invalid data in production.

This is only required for gitlab.com as we executed !107472 (merged) only for saas.

This will help to rebalance partition_id correctly in !108544 (closed).

It will not be a large percentage of the table, maybe 0.001 or even less. The indexes will cover the pipelines that were created in the incident window, before the application was restarted, which is around 5 hours.

For ci_job_variables adding the index concurrently as it's taking only 15 min. For the 2 others, went with async indexes as it takes more time.

• ci_build_trace_metadata --> 2 hours
• ci_job_artifacts --> 7 hours

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