build: Resync the GTest rules with upstream
build: Resync the GTest rules with upstream

Upstream GLib fixed the test rules to avoid repeating the test suite
three times.

robtaylor/json-glib-gvariant,ebassi/json-glib,oerdnj/json-glib,Distrotech/json-glib,ebassi/json-glib,oerdnj/json-glib,GNOME/json-glib,brauliobo/json-glib,Distrotech/json-glib,brauliobo/json-glib,Distrotech/json-glib,frida/json-glib,ebassi/json-glib,brauliobo/json-glib,GNOME/json-glib,oerdnj/json-glib,robtaylor/json-glib-gvariant,frida/json-glib,oerdnj/json-glib