Hide tooltip on view summary button on mouseout

What does this MR do and why?

If you click and quickly navigate away, the tooltip gets stuck, even if you click or hover over the button/elsewhere on the page. This introduces a small fix by hiding it again on mouseout (hover over the button again)

Screenshots or screen recordings

Before	After

How to set up and validate locally

• AI set up
• Additional feature flags :summarize_notes and :summarize_comments
• Go to issue > View summary (right of activity view, next to sort/filter button)
• Click button and quickly navigate away; tooltip should remain stuck
• Hover over button and out again, tooltip should disappear

#411677 (closed)