chore: upgrade api cube to 0.14

This new version includes a better handling of authentication token by reusing cubicweb's auth_tkt instead of relying on the experimental CW_JWT.

The way to configure the instance changed: instead of adding cubicweb_api.enable_login_route = yes to pyramid.ini, we now have to add cubicweb.includes = cubicweb_api.auth.routes.

See readme in https://forge.extranet.logilab.fr/cubicweb/cubes/api