Google has removed all of the UI from the OS to change this setting, but it's still changeable in other ways.
If an app has the WRITE_SECURE_SETTINGS
permission, it can do this by calling Settings.Secure.putInt(contentResolver, Settings.Secure.LOCATION_MODE, Settings.Secure.LOCATION_MODE_BATTERY_SAVING);
. The Tiles app in the Google Play Store includes a Location tile that does exactly this.
Alternatively, if you have ADB or root, you can do this with no third-party apps by running settings put secure location_providers_allowed +network,-gps
from an ADB shell or a root shell.