Make the build reproducible
Whilst working on the Reproducible Builds effort [0], we noticed that libdazzle could not be built reproducibly as it includes the absolute build path.
The glib-mkenums documentation recommends using @basename@ over @filename@ for this reason [1].
Patch attached.
[0] https://reproducible-builds.org/ [1] https://developer.gnome.org/gobject/stable/glib-mkenums.html#id-1.5.2.5.4