Consider removing matplotlib and seaborn as dependencies

[samuelstjean]

When running the example here https://mathurinm.github.io/celer/auto_examples/plot_lasso_cv.html#sphx-glr-auto-examples-plot-lasso-cv-py, the code reference the function configure_plt. While seemingly useful, it seems to be the only part calling in matplotlib and seaborn to set some graphics stuff, which could probably be removed as dependencies since it's the only place they are called.

This would both simplify maintenance and the list of packages used, as for example the function does not work since matplotlib 3.6.0 released in september 2022 https://matplotlib.org/stable/api/prev_api_changes/api_changes_3.6.0.html#checkdep-usetex-deprecated

Currently the example does not work because of this since the function was removed, which is easily side stepped for now.

[mathurinm]

Hi @samuelstjean, yes this makes sense
If you send the corresponding PR I'll merge it

[samuelstjean]

C'est dans #300.