ref: Add external contributor to CHANGELOG.md (getsentry#13400)

This PR adds the external contributor to the CHANGELOG.md file, so that
they are credited for their contribution. See getsentry#13395

Co-authored-by: mydea <2411343+mydea@users.noreply.github.com>

CHANGELOG.md

@@ -10,6 +10,8 @@
 
 - "You miss 100 percent of the chances you don't take. — Wayne Gretzky" — Michael Scott
 
+Work in this release was contributed by @charpeni. Thank you for your contribution!
+
 ## 8.26.0
 
 ### Important Changes