Update grid.cc #8632

Job	Run time
classicmode_1d_3dgrid	8m 1s
classicmode_3d	7m 16s
kilonova_1d_1dgrid	4m 27s
kilonova_1d_3dgrid	4m 23s
kilonova_2d_2dgrid	6m 11s
kilonova_2d_2dgrid_barnesthermalisation	5m 10s
kilonova_2d_2dgrid_expansionopac	4m 48s
kilonova_2d_2dgrid_xcomgammaphotoion	5m 6s
kilonova_2d_3dgrid	8m 27s
nebular_1d_3dgrid	11m 28s
nebular_1d_3dgrid_limitbfest	13m 21s
combine_checksums	18s
	1h 18m 56s

Provide feedback