WIP: Skip warning message on 401 error handling when anonymous user specifies author/assignee on Issues/Milestones

What does this MR do?

Skip warning message on 401 error handling when anonymous user specifies author/assignee on Issues/Milestones.

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

Can we guess all /api/... endpoint APIs as ones only for login users?

Why was this MR needed?

This should be removed as unnecessary warning message will make UX worse.

Screenshots (if relevant)

before

after

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• [n/a] Documentation created/updated
• [n/a] 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 #34285 (closed)