Hide Scroll Top button for failed Build page

What does this MR do?

This MR fixes the behavior where Scroll Top button appears overlapped on Header if build has failed and height of build trace is smaller than page height.

Why was this MR needed?

See #26040 (closed)

Screenshots (if relevant)

Before

After

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 #26040 (closed)