Missing automatic kernel selection for the jupyter notebooks in codespaces

[jlperla]

In the codespaces branch, it does not automatically pick the right default python kernel. This could be an upstream bug, but worth seeing if there is an additional setting necessary to choose the default for that (and/or the python kernel/environment?)

[jlperla]

It is important for this to be the activated environment as well - or perhaps the environment changes shouild be made to the default one. For example, I had the following issue on the htergoeneity lecture and it turned out that I had just accidentally chosen the wrong kernel, where the xgboost wasn't installed: