Nothing was broken. Repairs were posted. You have six months to implement the recommended repairs.
Only if your sensor.yaml file contains Template entities exclusively, in “modern” style, and the file is included under the template: key.
Chances are you still have sensor.yaml included under the sensor: key. Even if the file now contains only Template entities in “modern” style, it will fail to load because it’s not under the correct key.
Even if you now have the sensor.yaml file included under the template: key, it will still fail to load if the file contains the configuration of non-Template entities (like that google_wifi sensor in your example).
Everything you need to know about migrating from the “legacy” style of defining Template entities to the “modern” style is described here (same link as the one Didgeridrew recommended).
The “changes” were made several years ago when the legacy style of defining Template entities was deprecated in favor of modern style. The deprecated legacy format continued to be supported but all new features were implemented exclusively in “modern” style. Support for legacy format comes to an end in six months.
The “automated tools” come in the form of the repair which suggests how to convert the legacy configuration. It cannot automatically modify your files directly because, as a general policy, Home Assistant does not alter YAML files.