Edit help text to clarify that tags are annotated.

What does this MR do?

It's a small change to the help text when adding a message to a new tag.

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

I don't think so.

Why was this MR needed?

To address Issue #24554 (closed)

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?

#24554 (closed)