Backfill project_wiki_repositories table

What does this MR do and why?

As part of #367925 (closed), we introduced a new model to track project wiki repositories in the database. This MR backfills the project_wiki_repositories table for projects that still do not have an entry in this table.

How to set up and validate locally

1. Checkout the MR branch

   git fetch --all
   git checkout 367925-backfill-project-wiki-repositories

2. Run the database migrations

   bundle exec rails db:migrate

3. In a Rails console, check if the number of records in the project_wiki_repositories table matches the number of projects

   Project.count == Projects::WikiRepository.count

Migrations

• Raw SQL

  SELECT
      projects.id
  FROM
      projects
      LEFT OUTER JOIN project_wiki_repositories ON project_wiki_repositories.project_id = projects.id
  WHERE
      project_wiki_repositories.project_id IS NULL
  LIMIT 1000

• Query Plan

  • https://postgres.ai/console/gitlab/gitlab-production-tunnel-pg12/sessions/16105/commands/55422

MR acceptance checklist

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

• I have evaluated the MR acceptance checklist for this MR.

Related issue

Related to #367925 (closed)