Instead of explicitly add the target associated to the toolchain
if we use `build_nodeps` option let add an attribute base ourself on it
to know if we need to add it or not.
This way, we may have other dependency we must not skip.
First, we don't need to clone all the git repository, we only need a
sub-directory.
Secondly, as we the base_deps archives only archive the sub-directory,
subsequent run of kiwix-build in the ci will try to do a git update on
a non git repository.
By making ourselves a tar archive, we simplify the process.
The archive on download.kiwix.org has been made with :
`tar czf raspberrypy-tools.tar.gz raspberrypi-tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64`
`raspberrypi-tools` being a clone of `https://github.com/raspberrypi/tools`
commit sha is 5caa7046982f0539cf5380f94da04b31129ed521
Matthieu Gautier