It is not linked against so there is no need to include it in build inputs, much less propagate it.
This removes systemd.dev from the runtime closure of packages using pyudev.
The `buildPython*` function computes name from `pname` and `version`.
This change removes `name` attribute from all expressions in
`pkgs/development/python-modules`.
While at it, some other minor changes were made as well, such as
replacing `fetchurl` calls with `fetchPypi`.
