edit jupytext github action to preserve cell ids

[neptunes5thmoon]

I was playing around with the gh action and I think I found a way to preserve the cell ids which means there's no changes to the notebooks if the solution.py file hasn't changed and then the commit is avoided.

More specifically, the --update flag for jupytext preserves the cell id but also the output. So I instead remove the outputs with the nbconvert.

Haven't tested it super thorougly but e.g. this commit dlmbl/unet@4e917ed was not followed by a ghaction commit

[msschwartz21]

LGTM! Thanks for investigating this further :)

Should we remove the clear outputs for the solution notebook? Or leave a note somewhere that it's optional?

[neptunes5thmoon]

I hadn't considered keeping the outputs in the solution notebook before today. I'll play around with that a bit and then update

[neptunes5thmoon]

hmm, I think it's not straightforward to just keep the output cells. Problem is that any updates to solution.py don't show up in the notebook till the gh action is being run and what's kept are the old output cells without the updates. At least that's my understanding.

Not really sure how you get around that.

[msschwartz21]

Ok yeah that's a good point. Let's stick with removing the outputs and if someone is really committed to keeping the solution outputs they can figure out a different approach.