(#676): rsvg-convert - use gio's stdin/stdout streams for win32.
(#676): rsvg-convert - use gio's stdin/stdout streams for win32.

https://gitlab.gnome.org/GNOME/librsvg/-/issues/676

GNOME/librsvg,GNOME/librsvg,GNOME/librsvg,GNOME/librsvg