Update protobuf after python update for testing (#6638)

This fixes the issue where python client has
`AttributeError: 'NoneType' object has no attribute 'enum_types_by_name'
errors after python version is updated.

qa/L0_backend_python/setup_python_enviroment.sh

@@ -153,9 +153,8 @@ apt-get update && apt-get -y install \
                             "python3.${PYTHON_ENV_VERSION}-distutils" \
                             libboost-dev
 rm -f /usr/bin/python3 && \
-ln -s "/usr/bin/python3.${PYTHON_ENV_VERSION}" /usr/bin/python3 && \
-rm -r /usr/bin/python3.10
-pip3 install --upgrade install requests numpy virtualenv
+ln -s "/usr/bin/python3.${PYTHON_ENV_VERSION}" /usr/bin/python3
+pip3 install --upgrade install requests numpy virtualenv protobuf
 find /opt/tritonserver/qa/pkgs/ -maxdepth 1 -type f -name \
     "tritonclient-*linux*.whl" | xargs printf -- '%s[all]' | \
     xargs pip3 install --upgrade