package-native.sh should force libdisplay-info subproject

This ensures that the script produces a build similar to the default steamrt build, even if libdisplay-info is available on the build system root.

package-native.sh

@@ -63,6 +63,7 @@ function build_arch {
         --bindir "$2"                        \
         --libdir "$2"                        \
         -Dbuild_id=$opt_buildid              \
+        --force-fallback-for=libdisplay-info \
         "$DXVK_BUILD_DIR/build.$1"
 
   cd "$DXVK_BUILD_DIR/build.$1"