Schedule ci_builds FK indexes for async creation

What does this MR do and why?

Related to #382033 (closed)

For partitioning ci_builds we need to update all FKs that reference it to use the partitioning column and each FK needs to have an index. For these two tables the index creation takes too long to be executed as post deployment migrations:

• !110392 (comment 1255690177) - 2.7 hours for index_ci_build_trace_metadata_on_partition_id_build_id
• !110395 (comment 1255704712) - 7.5 hours for index_ci_job_artifacts_on_partition_id_job_id

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