fix: guard CI variable access in plot_frequencies_time_series and plo…#1037

jonbrenas merged 7 commits intomalariagen:mastermalariagen/malariagen-data-python:masterfrom

adilraza99:GH1035-plot-ci-guardadilraza99/malariagen-data-python:GH1035-plot-ci-guardCopy head branch name to clipboard