Allow disabling the test suite
The GTK-Doc test suite depends on GLib/GObject, which creates a circular dependency between GLib and GTK-Doc. By adding an option to build GTK-Doc without its test suite, we can break the circular dependency.
The GTK-Doc test suite depends on GLib/GObject, which creates a circular dependency between GLib and GTK-Doc. By adding an option to build GTK-Doc without its test suite, we can break the circular dependency.