Strip kernel info from jupyter notebooks

[dpanici]

If you use jupyter locally, you often change the kernel to match your conda env (desc-env or whatever), but the CI does not make a conda env, they just install in the base python environment. This causes issues where the jupyter wants to find desc-env but cannot, and you have to instead manually change the kernel of the jupyter back to the base Python kernel before saving and uploading to git.

Would be nice to automatically strip the kernel info to avoid this annoyance

[dpanici]

pre-commit hook to check if a notebook was changed and if so, to strip the kernel info from it

[YigitElma]

https://github.com/PlasmaControl/DESC/pull/1498#issuecomment-2578440156