Backport of "Execute BBM affected by single record table bug"

What does this MR do and why?

Backport !227592 (merged) into 18.9. This executes all migration affected by the bug fixed with !224446 (merged).

How to test

The best way is to test on a fresh Omnibus install as described in this snippet:

1. Install 18.7.0
2. Create single record for pool_repositiories
   • in sudo gitlab-rails c session

     class TestProject < ApplicationRecord
        self.table_name = 'projects'
      end
     
     project = TestProject.create!(organization_id: 1, namespace_id: 1, project_namespace_id: 1, name: 'Project 1', path: 'project-1')

   • in sudo gitlab-psql session

     drop trigger pool_repositories_loose_fk_trigger on pool_repositories ;
     insert into pool_repositories (shard_id, source_project_id) select 1, id from projects limit 1;
     create trigger pool_repositories_loose_fk_trigger AFTER DELETE ON pool_repositories REFERENCING OLD TABLE AS old_table FOR EACH STATEMENT EXECUTE FUNCTION insert_into_loose_foreign_keys_deleted_records();

3. Upgrade to 18.8.0, background migration finished but the row in pool_repositories will not be updated.
4. Upgrade to 18.9.0. This will fail with PG::CheckViolation: ERROR: check constraint "check_96233d37c0"...
5. Copy the migration
6. Execute sudo gitlab-rails db:migrate, all migrations should succeed
7. Retry upgrade, it should succeed

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• This MR is backporting a bug fix, documentation update, or spec fix, previously merged in the default branch.
• The MR that fixed the bug on the default branch has been deployed to GitLab.com (not applicable for documentation or spec changes).
• The MR title is descriptive (e.g. "Backport of 'title of default branch MR'"). This is important, since the title will be copied to the patch blog post.
• Required labels have been applied to this merge request
  • severity label and bug subtype labels (if applicable)
  • If this MR fixes a bug that affects customers, the customer label has been applied.
• This MR has been approved by a maintainer (only one approval is required).
• Ensure the e2e:test-on-omnibus-ee job has succeeded, or if it has failed, investigate the failures. If you determine the failures are unrelated, you may proceed. If you need assistance investigating, reach out to a Software Engineer in Test in #s_developer_experience.

Note to the merge request author and maintainer

If you have questions about the patch release process, please:

• Refer to the patch release runbook for engineers and maintainers for guidance.
• Ask questions on the #releases Slack channel (internal only).
• Once the backport has been merged, the commit changes will be automatically deployed to a release environment that can be used for manual validation. See after merging runbook for details.