This reverts commit e3f9c4d79041c6114a67ff67772186b737477393.
This fixes#72791.
Version 2.0.13 of pyspf introduced a bug where some incoming mails can cause a
crash and be falsely rejected. (https://github.com/sdgathman/pyspf/issues/17)
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`.