Remove last_reset from vesync sensor (home-assistant#63877)

Author: emontnemery

homeassistant/components/vesync/sensor.py

@@ -1,5 +1,4 @@
 """Support for power & energy sensors for VeSync outlets."""
-from datetime import datetime
 import logging
 
 from homeassistant.components.sensor import (
@@ -126,11 +125,6 @@ def device_class(self):
         """Return the energy device class."""
         return SensorDeviceClass.ENERGY
 
-    @property
-    def last_reset(self):
-        """Return datetime representing beginning of day."""
-        return datetime.today()
-
     @property
     def native_value(self):
         """Return the today total energy usage in kWh."""