Finalize migration for the `*_pipeline_id` of `vulnerabilty_occurrences`

Summary

As part of the epic to delete vulnerability_occurrence_pipelines table, we created a batched background migration (!147220 (merged))

As described in the batched background migration documentation, we must finalize the migration once it is complete

Implementation Plan

• verify the batched background migration is completed on GitLab.com
  • can be done by running this chatops command:

    /chatops run batched_background_migrations status 1000544 --production

  • also tracked by this work item: ✅ (100% complete) | monitor progress of backfill (#462417 - closed) • Michael Becker • 17.1
• verify the migration was added in or before the last required stop
  • update: Based on this discussion, we are ok to finalize without waiting for a required stop
  • I think 17.0 is a required stop
  • chatops say the migration from !147220 (merged) was available in v17.1.0-ee

  /chatops run release check https://gitlab.com/gitlab-org/gitlab/-/merge_requests/147220

• Write a new migration using the ensure_batched_background_migration_is_finished helper as described in the docs