Google contacts sync issue since October, 2021

At the beginning of October 2021, Google closed its API Google Contact v3 for contact synchronization. A message was sent by email by Google to say the service has been deprecated but the fact shows that the service is completely closed. Calling an API to get a contact return often the error "Contacts API is being deprecated" instead of the expected result.
If you use an external module (for example the Google module) with active contact synchronization, this results in malfunctions in the management of the contact under Dolibarr since that date. As the change appeared on the Google servers side, there is not much you can do except turn off contact sync.

If you were using a custom development or external non official module in this case, it is simply no longer possible to use the contact synchronization functions. Ony available solution is to wait for an evolution of your external modules which are based on this service in order to work on the new API "People" offered by Google to replace the closed service.