Add grpc in CODEOWNERS

Signed-off-by: Chang Su <chang.s.su@oracle.com>

Author: CatherineSue

.github/CODEOWNERS

@@ -158,3 +158,7 @@ mkdocs.yaml @hmellor
 /docs/usage/security.md @russellb
 /SECURITY.md @russellb
 /docs/contributing/vulnerability_management.md @russellb
+
+# gRPC server
+/vllm/grpc @CatherineSue @slin1237
+/vllm/entrypoints/grpc_server.py @CatherineSue @slin1237