build: Get rid of maintainer mode where gdbus-codegen is used
It now (glib 2.83.3) adds GLIB_VERSION_2_84 macro to the generated code, so we need to let the user generates these files himself.
Related: xfce4-panel#904 (closed)
It now (glib 2.83.3) adds GLIB_VERSION_2_84 macro to the generated code, so we need to let the user generates these files himself.
Related: xfce4-panel#904 (closed)