Delete invalid protected ref access levels

What does this MR do and why?

This change is meant to add background migrations to clean up invalid protected ref access levels that may have been created as a result of changes that are reverted in: !133480 (merged).

That is any access levels that are for a group that the project of the protected branch does not have a project_group_link to should be deleted.

Query plans:

• protected_branch_merge_access_levels:
  • https://console.postgres.ai/gitlab/gitlab-production-tunnel-pg12/sessions/23613/commands/75889
• protected_branch_push_access_levels
  • https://console.postgres.ai/gitlab/gitlab-production-tunnel-pg12/sessions/23613/commands/75892
• protected_tag_create_access_levels:
  • https://console.postgres.ai/gitlab/gitlab-production-tunnel-pg12/sessions/23613/commands/75895

Contributes to: #427486 (closed)

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