Fix issue numbers on milestone page

What does this MR do?

Fixes regression where issue numbers were not being rendered on the issue milestone page.

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

None

Why was this MR needed?

Fixes regression in %8.16 rc

Screenshots (if relevant)

Before:

After:

Does this MR meet the acceptance criteria?

• Tests
  • 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 #26772 (closed)