Do not use gdk-pixbuf2 even if it is installed.

There doesn't seem to be a way to disable this other than patching:

https://github.com/caolanm/libwmf/issues/30
--- configure.orig	2026-04-05 09:11:50.000000000 -0500
+++ configure	2026-04-30 19:50:14.000000000 -0500
@@ -17658,7 +17658,7 @@
 GDK_PIXBUF_LIBS=""
 GDK_PIXBUF_DIR=""
 
-if test $LIBWMF_BUILDSTYLE != lite; then
+if false; then
 
 pkg_failed=no
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for gdk-pixbuf-2.0 >= 2.1.2" >&5