Finalize data migrations necessary for raw_metadata removal

Why are we doing this?

All batched background migrations need to be finalized. In c9d9a3bb we removed the rescheduling post-deployment migration but never finalized it. As such we need to finalize this.

Implementation Plan

1. Restore the class and the logic for MigrateEvidencesForVulnerabilityFindings and MigrateRemediationsForVulnerabilityFindings from 842d4283
2. Find and restore MigrateLinksForVulnerabilityFindings it was finalized in db/post_migrate/20241112161753_finalize_migrate_links_for_vulnerability_findings.rb and restored in 36f0411c
3. Proceed according to https://docs.gitlab.com/development/database/batched_background_migrations/#finalize-a-batched-background-migration for all of the migrations.