Delete TODO notes about restarts timing out.
Delete TODO notes about restarts timing out.

https://github.com/jupyter/notebook/issues/3705 noted some issues with kernel messages. I think these were mainly because we disconnected and reconnected the websocket on restart. We no longer do this, and these tests seem to pass, so let’s remove the TODO and keep an eye on it.
jupyter/jupyterlab,jupyter/jupyterlab,jupyter/jupyterlab,jupyter/jupyterlab,jupyter/jupyterlab