'openstack undercloud upgrade' command fails with "ERROR: The Resource Type (OS::TripleO::UndercloudServices) could not be found"

Issue

During a fast-forward upgrade from OpenStack 13 to 16.1, when you issue the command 'openstack undercloud upgrade -y' you get different errors like this in /home/stack/undercloud-install.log:

2021-08-24 11:25:00.369 3521 WARNING tripleoclient.v1.tripleo_deploy.Deploy [  admin] ** Performing Heat stack create.. **
2021-08-24 11:25:00.621 3521 ERROR tripleoclient.v1.tripleo_deploy.Deploy [  admin] Exception: ERROR: The Resource Type (OS::TripleO::UndercloudServices) could not be found.

or

heatclient.exc.HTTPBadRequest: ERROR: The Resource Type (OS::TripleO::Undercloud::NodeUserData) could not be found.