Improve mqtt sensor options validion logging (#127631)

* Improve mqtt sensor options validion logging

* Fix test

homeassistant/components/mqtt/sensor.py

@@ -100,7 +100,7 @@ def validate_sensor_state_and_device_class_config(config: ConfigType) -> ConfigT
 
         if (device_class := config.get(CONF_DEVICE_CLASS)) != SensorDeviceClass.ENUM:
             raise vol.Invalid(
-                f"The option `{CONF_OPTIONS}` can only be used "
+                f"The option `{CONF_OPTIONS}` must be used "
                 f"together with device class `{SensorDeviceClass.ENUM}`, "
                 f"got `{CONF_DEVICE_CLASS}` '{device_class}'"
             )

tests/components/mqtt/test_sensor.py

@@ -956,7 +956,7 @@ async def test_invalid_state_class(
                     }
                 }
             },
-            "The option `options` can only be used together with "
+            "The option `options` must be used together with "
             "device class `enum`, got `device_class` 'gas'",
         ),
         (