vp-comparefits blows up memory

Created by: Zaharid

If I run comparefits like

vp-comparefits NNPDF40_nnlo_as_01180_corr_s2 NNPDF40_nnlo_as_01180_corr_s2 --title="test" --author="Zahari Kassabov" --keywords="test" --debug

with a fully updated conda environment I see that the memory usage blows up to over 32 Gb, causing it to swap and never finish. I think that is because of the inclusion of the overfitting metric. This causes a lot of overhead by things like

[DEBUG]: Found sep_mult for spec (('dataspecs', 0), ('t0_info', 0), ('t0_info', 0), ('pdfreplicas', 25), 'fitenvironment', ('group_dataset_inputs_by_experiment', 0)) at 6

which involves blowing many things over replicas.

Collecting over replicas is not a very good idea.