hooks aren't found in JupyterLab

Hi. I've got an issue with hooks not being found in JupyterLab. First of all, both my terminal and my JupyterLab instance are running on the same activated conda environment. I've checked to make sure I have the latest version of nbdev (2.3.12).

When I run nbdev hooks from iTerm, they work just fine. You'll see an error but that just proves that the command was indeed called.


But when I run the same command in the JupyterLab terminal, I get an "command not found" error. However, as you can see, I can still run the `nbdev_export` manually with `./env/bin/nbdev_export`.


This wouldn't be that big of a deal, except I'll be doing a [tutorial](https://cfp.scipy.org/2023/talk/NFWZXD/) at SciPy about creating complex web applications with jupyter widgets + voila + nbdev here in about exactly a month, and I'll need participants to be able to run these commands from the JupyterLab terminal specifically. Any help on this issue would be much appreciated :)

Beginne damit, den Befehl `nbdev hooks` in der iTerm-Umgebung mit dem JupyterLab-Terminal zu vergleichen, in dem `./env/bin/nbdev_export` weiterhin manuell ausgeführt wird. Verfolge die von jedem Terminal verwendete Umgebung und ermittle, warum der nbdev-Befehl nicht gefunden wird; abgeschlossen ist die Aufgabe, wenn nbdev hooks direkt im JupyterLab-Terminal ausgeführt wird.

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