Update requirements.txt

Author: RodgerZhu

cczoo/tensorflow-serving-cluster/tensorflow-serving/docker/client/requirements.txt

@@ -2,7 +2,7 @@ argparse
 aiohttp>=3.7.0
 grpcio>=1.34.0
 opencv-python>=4.4.0
-tensorflow==2.11.1
+tensorflow==2.12.1
 tensorflow-serving-api==2.6.2
 protobuf==3.19.5