Google has announced that it will be changing the Google Photo's API. This will mean that the integration will no longer be able to access photo's which are not uploaded by the integration itself. In my view this defeats the purpose of this integration, and it will be deprecated on March 31, 2025.
Starting from HA 2024.10, there will be an official Google Photos integration with the limitations mentioned before: https://rc.home-assistant.io/integrations/google_photos.
More information here: #64