update og image for stacking

Signed-off-by: oppiliappan <[e-mail]>

pages/blog/stacking.md

···
 title: jujutsu on tangled
 subtitle: tangled now supports jujutsu change-ids!
 date: 2025-06-02
-image: /static/img/hidden-ref.png
+image: /static/img/interdiff_difference.jpeg
 authors:
   - name: Akshay
     email: [e-mail]