Ensure traversal_ids background migrations are complete

What does this MR do and why?

We performed a background migration to backfill the namespaces.traversal_ids column in %14.0. There are multiple temporary indexes to remove that are only required by the background migrations. Before any index removal occurs we need to ensure that the migrations are completed.

This MR will forcefully ensure the background migrations are complete by performing any lingering jobs.

Closes #335473 (closed)

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