Merge branch 'tb/add-objects-in-unpacked-packs-simplify'

Code simplification with reduced memory usage. * tb/add-objects-in-unpacked-packs-simplify: builtin/pack-objects.c: remove duplicate hash lookup builtin/pack-objects.c: simplify add_objects_in_unpacked_packs() object-store.h: teach for_each_packed_object to ignore kept packs