Revert "[jupyterhub] add vim plugin"

This reverts commit 2a94bf29.

jupyterhub/Dockerfile

@@ -31,8 +31,7 @@ RUN python${PYTHON_VERSION} -m pip --no-cache-dir install \
     python${PYTHON_VERSION} -m jupyter labextension install \
         jupyter-webrtc \
         ipyvolume \
-        jupyter-threejs \
-        jupyterlab_vim
+        jupyter-threejs
 
 RUN mkdir -p ~/.venv && \
     python${PYTHON_VERSION} -m venv ~/.venv/robofish && \