component/gdk-pixbuf: add slapos python3 in PATH

component/gtk-2/buildout.cfg

@@ -95,7 +95,7 @@ configure-command = ${meson:location}/bin/meson builddir --wrap-mode=nodownload
 make-binary = ninja -C builddir
 pkg_config_depends = ${glib:location}/lib/pkgconfig:${glib:pkg_config_depends}:${libX11:location}/lib/pkgconfig:${libX11:pkg_config_depends}:${libpng:location}/lib/pkgconfig:${libjpeg:location}/lib/pkgconfig:${libtiff:location}/lib/pkgconfig
 environment =
-  PATH=${glib:location}/bin:${perl:location}/bin:${ninja:location}/bin:${pkgconfig:location}/bin:${xz-utils:location}/bin:${libpng:location}/bin%(PATH)s
+  PATH=${glib:location}/bin:${perl:location}/bin:${python3:location}/bin:${ninja:location}/bin:${pkgconfig:location}/bin:${xz-utils:location}/bin:${libpng:location}/bin%(PATH)s
   PKG_CONFIG_PATH=${:pkg_config_depends}
   CFLAGS=-I${gettext:location}/include
   LDFLAGS=-L${gettext:location}/lib -Wl,-rpath=${gettext:location}/lib -Wl,-rpath=${glib:location}/lib -Wl,-rpath=${jbigkit:location}/lib -Wl,-rpath=${libtiff:location}/lib -Wl,-rpath=${libjpeg:location}/lib -Wl,-rpath=${libpng:location}/lib -Wl,-rpath=${zlib:location}/lib -Wl,-rpath=@@LOCATION@@/lib