Prevent a spec from failing in `spec/features/merge_requests/diff_notes_resolve_spec.rb`

What does this MR do?

Fixes a failing spec in spec/features/merge_requests/diff_notes_resolve_spec.rb

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Tests failing on master. RSpec executes inner before blocks after outer before blocks, so the second note was being added after loading the page, and then being pulled in by running JS on the page, causing intermittent failures if we clicked the resolve button before the note was loaded.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• 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 #23875 (closed)