Remove percentages from DevOps Score no-load icons

What does this MR do?

DevOps Score renders special icons 1) if Usage Ping is disabled or 2) if there is no data available. Previously both of these 2 icons included percentages that misled users because they looked real when they were essentially decorative. This removes those percentage numbers.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Related to #19475 (closed).