BUG: abg_python leaks Matplotlib configuration (side effects at import time)

[neutrinoceros]

This was discovered as the root cause of yt-project/yt#4785, see in particular yt-project/yt#4785 (comment)

Showcasing culprit lines:

abg_python/src/abg_python/plot_utils.py

Lines 26 to 27 in 408f0da

	plt.rcParams['figure.dpi'] = 120
	plt.rcParams['figure.facecolor'] = 'white'

This one also has potentially undesirable side effects at import time (though it was never a problem in yt's CI, it could create issues for firefly users that could be pretty hard to debug)

abg_python/src/abg_python/plot_utils.py

Line 5 in 408f0da

matplotlib.use("Agg")

I've tried simply dropping these three lines, which didn't break any tests from the package, so I assume they are actually disposable, but I don't know why they were added in the first place so let me know if that solution doesn't work for you.

[agurvich]

Hey @neutrinoceros , so sorry for this... These lines were put in to save me trouble setting them for copying plots into slack for my thesis advisor. God willing, these lines will never be necessary again :')

[agurvich]

merged and uploaded 1.1.5 to pypi... hopefully that gets the CI back on track. thanks @neutrinoceros !