Drop unused BuildRequires: pkgconfig(dbus-glib-1)
    
    ...which had originally been added with 38ee1f0e29947913192d3566e1d47cfd3e51b18e
    "add missing build dep", but without any further information.  (And then changed
    from an explicit dbus-glib-devel to the current pkconfig(dbus-glib-1) in
    fb9ee009aecca813d1286988a190b49050bb449a "update build deps to Packaging
    Guidelines".)  But it appears to be completely unused by now.