Remove records with action=approvals from system_note_metadata

What does this MR do?

It removes the records with action = 'approvals' from system_note_metadata table.

Why was this MR needed?

We introduced system_note_metadata table in 9.1. We split approvals action into approved and unapproved after the deployment. That caused that we now have in the database incorrect values.

Right now the system behaves the same no matter if there is metadata record with approvals in action or no record at all. However we don't want to keep these old incorrect data in the database.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

closes #2192 (closed)