gtk4: fix qa error with gstreamer PACKAGECONFIG

When gstreamer PACKAGECONFIG is enabled, packaging fails with the following error:

ERROR: gtk4-4.6.9-r0 do_package: QA Issue: gtk4: Files/directories were installed but not shipped in any package:
  /usr/lib/gtk-4.0/4.0.0/media/libmedia-gstreamer.so

Fix it by packaging this file also.

Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>

meta-gnome/recipes-gnome/gtk4/gtk4_4.6.9.bb

@@ -95,6 +95,7 @@ FILES:${PN}:append = " \
     ${datadir}/gtk-4.0/emoji/ \
     ${datadir}/metainfo/ \
     ${datadir}/icons/hicolor/*/apps/org.gtk.PrintEditor4*.* \
+    ${libdir}/gtk-4.0/${LIBV}/media \
     ${libdir}/gtk-4.0/${LIBV}/printbackends \
     ${bindir}/gtk4-update-icon-cache \
     ${bindir}/gtk4-launch \