Fix tooltip position in mini pipeline chart

What does this MR do?

This fixes the tooltip position the mini pipeline chart, when 2 jobs (no more, no less ¯_(ツ)_/¯)were present the tooltip would always target the last element in the list

#220762 (closed)

Screenshots (strongly suggested)

Before	After

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because _____.
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content