CI assumes "name": "python3" so if people are using nb_conda_kernels locally or some other kernel name, building the book fails with "jupyter_client.kernelspec.NoSuchKernel: No such kernel named conda-env-xarray-tutorial-py" (#76 (review), #74 (comment))

For compatibility with binder we want a standard "name":"python3" for all notebooks, so could add a check to https://github.com/xarray-contrib/xarray-tutorial/blob/main/.github/workflows/qaqc.yaml