chore: Add external contributor to CHANGELOG.md (#18473)

This PR adds the external contributor to the CHANGELOG.md file, so that
they are credited for their contribution. See #17835

Co-authored-by: andreiborza <168741329+andreiborza@users.noreply.github.com>
Co-authored-by: Nicolas Hrubec <nico.hrubec@sentry.io>

Author: 3 people

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 - "You miss 100 percent of the chances you don't take. — Wayne Gretzky" — Michael Scott
 
+Work in this release was contributed by @sebws. Thank you for your contribution!
+
 ## 10.30.0
 
 - feat(nextjs): Deprecate Webpack top-level options ([#18343](https://github.com/getsentry/sentry-javascript/pull/18343))