Fix edit scoped label spec

What does this MR do?

Fixes flaky test for editing scoped labels by switching out the method of blurring the label dropdown by clicking the issue title instead of using click_body which sometimes clicks things it shouldn't.

Closes #37265 (closed)

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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