meta: add test/reporters to codeowners

PR-URL: nodejs/node#49186
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>

graal-nodejs/.github/CODEOWNERS

@@ -148,6 +148,7 @@
 /lib/internal/main/test_runner.js @nodejs/test_runner
 /lib/internal/test_runner/* @nodejs/test_runner
 /lib/test.js @nodejs/test_runner
+/lib/test/reporters.js @nodejs/test_runner
 /test/parallel/test-runner-* @nodejs/test_runner
 
 # Single Executable Applications