FR: clone `packages` repo in shallow mode (`--depths=1`)

[ZoomRmc]

atlas/src/basic/gitops.nim

Line 112 in 839c158

elif ShallowClones in context().flags: "--depth=1"

atlas/src/basic/packageinfos.nim

Line 108 in 839c158

let res = clone(parseUri "https://github.com/nim-lang/packages", pkgsDir)

Currently the clone operation is global-configured to use shallow cloning. Atlas needs to pass this option to clone directly or ignore it when cloning the packages repo. In my setup shallow cloning packages brings it down to 1,1M from 5,4M. Considering this is for each project, this is pretty significant.

BTW, is there a reason to keep separate packages clone for each deps directory and not use a global one?