packages: Remove libiconv from Windows packaging
packages: Remove libiconv from Windows packaging

This glib dependency is not needed on Windows since glib uses its
internal copy of iconv.

nirbheek/cerbero,fluendo/cerbero,fluendo/cerbero,atsushieno/cerbero,atsushieno/cerbero,nirbheek/cerbero,atsushieno/cerbero,nirbheek/cerbero,atsushieno/cerbero,GStreamer/cerbero,fluendo/cerbero,fluendo/cerbero,GStreamer/cerbero,GStreamer/cerbero,GStreamer/cerbero,nirbheek/cerbero,atsushieno/cerbero,GStreamer/cerbero,fluendo/cerbero