Remove Lock Icon on Protected Tag

What does this MR do?

Removes lock icon on protected tag in repository branch view.

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

No, the change is very small.

Why was this MR needed?

In #22111 (closed) it was decided that the lock icon was inconsistent with the visual style of rest of the similar tags.

Screenshots (if relevant)

Before:

After:

Both images were taken from the original issue, but the final result is visually the same.

Does this MR meet the acceptance criteria?

• Changelog entry added
• N/A Documentation created/updated
• N/A API support added
• Tests
  • N/A 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 #22111 (closed)