tests require Jupyter extension to be installed

[peterj]

Note that when running tests, you need to install the Jupyter extension in the test VSCode instance. I've done it manually, however, I bet there has to be a way to automatically install that extension as a dependency.

[rebornix]

This can be archived by adding ms-toolsai.jupyter to extensionDependencies in package.json.

[seeM]

Closing, seems to be solved in main:

https://github.com/fastai/nbdev-vscode/blob/4da09a4d985eea47c9dca904da0e1d1defd390c4/package.json#L12-L14