Fixes styling issues in test reports

What does this MR do?

1. Removes extra border
2. Removes extra space for the loading icon

What are the relevant issue numbers?

Closes #52147 (closed) and gitlab-org/gitlab-ce#51386

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• [n.a.] Documentation created/updated
• [n.a.] Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• [n.a.] Conforms to the database guides