Starting from May 30th, 2022 10:00 CEST:
The site resource object returned by the CMA will no longer expose the following properties:
attributes.frontend_url: this was deprecated years ago in favor of multiple build triggers per project;relationships.menu_items: use the dedicated endpoint to retrieve the list of menu items;relationships.users: use the dedicated endpoint to retrieve the list of collaborators;relationships.sso_users: use the dedicated endpoint to retrieve the list of SSO users;relationships.roles: use the dedicated endpoint to retrieve the list of roles;relationships.build_triggers: use the dedicated endpoint to retrieve the list of build triggers.