build: Sync the interface age with the version
build: Sync the interface age with the version

Like we do in the Meson build, the Autotools build should reset the
interface age every time we do a development cycle.

GNOME/json-glib,ebassi/json-glib,ebassi/json-glib,frida/json-glib,ebassi/json-glib,frida/json-glib,GNOME/json-glib