added appex-qa in CODEOWNERS for scout painless lab tests

Author: fake-haris

.github/CODEOWNERS

@@ -1657,7 +1657,7 @@ src/platform/plugins/shared/discover/public/context_awareness/profile_providers/
 /x-pack/platform/plugins/shared/maps/ui_tests @elastic/appex-qa # temporarily
 /x-pack/platform/plugins/private/discover_enhanced/ui_tests/ @elastic/appex-qa # temporarily
 /x-pack/platform/plugins/private/discover_enhanced/ui_tests/tests/discover_cdp_perf.spec.ts @elastic/kibana-data-discovery # test tracks bundle size limits
-/x-pack/platform/plugins/private/painless_lab/ui_tests # temporarily
+/x-pack/platform/plugins/private/painless_lab/ui_tests @elastic/appex-qa # temporarily
 /x-pack/test/functional/fixtures/package_registry_config.yml @elastic/appex-qa # No usages found
 /x-pack/test/functional/fixtures/kbn_archiver/packaging.json @elastic/appex-qa # No usages found
 /x-pack/test/functional/es_archives/filebeat @elastic/appex-qa