testing-repository/Gtk4/gtk56_menu_test2/res/gtk56.resources.xml

<?xml version="1.0" encoding="UTF-8"?>
<gresources>
    <gresource prefix="gtk56">
        <file>icon.png</file>
        <file preprocess="xml-stripblanks">menubar.ui</file>
    </gresource>
</gresources>