title: Deprecation warning from Jupyter: "`should_run_async` will not call `transform_cell` automatically in the future"
body: <p>When I import a package I get the following deprecation message. I can't find any documentation about it. I know I can suppress the warnings but I would like to know what's happening.</p>
  <pre><code>import pandas as pd
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/ipykernel/ipkernel.py:287: DeprecationWarning: `should_run_async` will not call `transform_cell` automatically in the future. Please pass the result to `transformed_cell` argument and any exception that happen during thetransform in `preprocessing_exc_tuple` in IPython 7.17 and above.
    and should_run_async(code)
  </code></pre>
  <p>Installation: Python 3.8.5, jupyter-client 6.1.6, jupyter-core 4.6.3, jupyterlab              2.2.4,
  jupyterlab-server             1.2.0 on Mac OS</p>