Improve type hints in demo and mqtt number entity (#76464)

homeassistant/components/demo/number.py

@@ -131,7 +131,7 @@ class DemoNumber(NumberEntity):
             name=self.name,
         )
 
-    async def async_set_native_value(self, value):
+    async def async_set_native_value(self, value: float) -> None:
         """Update the current value."""
         self._attr_native_value = value
         self.async_write_ha_state()

homeassistant/components/mqtt/number.py

@@ -272,7 +272,7 @@ class MqttNumber(MqttEntity, RestoreNumber):
         return self._config.get(CONF_UNIT_OF_MEASUREMENT)
 
     @property
-    def native_value(self):
+    def native_value(self) -> float | None:
         """Return the current value."""
         return self._current_number