chore: Add external contributor to CHANGELOG.md (#18637)

This PR adds the external contributor to the CHANGELOG.md file, so that
they are credited for their contribution. See #18492

Co-authored-by: Lukas Stracke <lukas.stracke@sentry.io>

Author: HazAT

CHANGELOG.md

@@ -4,7 +4,7 @@
 
 - "You miss 100 percent of the chances you don't take. — Wayne Gretzky" — Michael Scott
 
-Work in this release was contributed by @xgedev and @sebws. Thank you for your contributions!
+Work in this release was contributed by @xgedev, @Mohataseem89 and @sebws. Thank you for your contributions!
 
 - ref(nextjs): Drop `resolve` dependency from the Next.js SDK ([#18618](https://github.com/getsentry/sentry-javascript/pull/18618))