use matplotlib for charts

[afeld]

Plotly has been a recurring pain in the neck, mainly around its dependencies:

python-public-policy/extras/environment.yml

Lines 24 to 44 in aefb1fb

	# newer than what's on Colab, in order to include
	# https://github.com/plotly/plotly.py/pull/4379
	- plotly=5.24.1
	- requests=2.32.3
	- statsmodels=0.14.3
	## supporting packages for notebooks ##
	# makes kernel available in JupyterHub
	- ipykernel
	- ipytest=0.14.*
	- wget
	# https://plotly.com/python/static-image-export/
	- python-kaleido
	# required for plotly rendering
	# https://github.com/plotly/plotly.py/blob/94f2024bc981bdfd3d4ba527122a21286f4c7793/packages/python/plotly/plotly/io/_renderers.py#L395
	- nbformat
	# necessary optional dependency for nbformat->jsonschema
	# https://python-jsonschema.readthedocs.io/en/stable/validate/#validating-formats
	- isoduration
	# needed for plotly
	# https://plotly.com/python/getting-started/#jupyterlab-support
	- ipywidgets>=7.6

...and rendering in JupyterLab + the PDF export. Rendering images as data URLs using the plotting functionality built into pandas seems way simpler. Downside is that the charts aren't as cool.