fix ray install (#1630)

docker/Dockerfile-cloud-no-tmux

@@ -16,7 +16,7 @@ COPY scripts/motd /etc/motd
 RUN pip install jupyterlab notebook ipywidgets && \
     jupyter lab clean
 RUN apt install --yes --no-install-recommends openssh-server tmux sudo && \
-    pip3 install -U --no-cache-dir grpcio ray==2.9.3 && \
+    pip3 install -U --no-cache-dir grpcio ray[default]==2.9.3 && \
     mkdir -p ~/.ssh && \
     chmod 700 ~/.ssh && \
     printf "[ ! -z \"\$TERM\" -a -r /etc/motd ] && cat /etc/motd\n" >> ~/.bashrc && \