Update sn3d.cc #8644

Job	Run time
classicmode_1d_3dgrid	8m 14s
classicmode_3d	6m 55s
kilonova_1d_1dgrid	4m 10s
kilonova_1d_3dgrid	5m 28s
kilonova_2d_2dgrid	7m 41s
kilonova_2d_2dgrid_barnesthermalisation	6m 17s
kilonova_2d_2dgrid_expansionopac	5m 20s
kilonova_2d_2dgrid_xcomgammaphotoion	5m 43s
kilonova_2d_3dgrid	6m 15s
nebular_1d_3dgrid	9m 32s
nebular_1d_3dgrid_limitbfest	12m 2s
combine_checksums	18s
	1h 17m 55s

Provide feedback