chore: Add external contributor to CHANGELOG.md (#15606)

This PR adds the external contributor to the CHANGELOG.md file, so that
they are credited for their contribution. See #15603

---------

Co-authored-by: s1gr1d <32902192+s1gr1d@users.noreply.github.com>
Co-authored-by: Abhijeet Prasad <aprasad@sentry.io>

CHANGELOG.md

@@ -10,7 +10,7 @@
 
 - "You miss 100 percent of the chances you don't take. — Wayne Gretzky" — Michael Scott
 
-Work in this release was contributed by @msurdi-a8c and @namoscato. Thank you for your contributions!
+Work in this release was contributed by @msurdi-a8c, @namoscato, and @rileyg98. Thank you for your contributions!
 
 ## 9.4.0