The Google Pixel 6 and Pixel 6 Pro still do not have a face unlock, six months after they were released. That may be set to change shortly, though, as a Pixel 6 owner has revealed sighting of a face unlock option in their phone's settings.
https://www.notebookcheck.net/Face-unlock-option-appears-in-Google-Pixel-6-screen-lock-settings.613075.0.html