Move MQTT CONF_SCHEMA from light and vacuum to .const (#81152)

Move CONF_SCHEMA to .const

homeassistant/components/mqtt/const.py

@@ -19,6 +19,7 @@ CONF_ENCODING = "encoding"
 CONF_KEEPALIVE = "keepalive"
 CONF_QOS = ATTR_QOS
 CONF_RETAIN = ATTR_RETAIN
+CONF_SCHEMA = "schema"
 CONF_STATE_TOPIC = "state_topic"
 CONF_STATE_VALUE_TEMPLATE = "state_value_template"
 CONF_TOPIC = "topic"

homeassistant/components/mqtt/light/schema.py

@@ -1,7 +1,7 @@
 """Shared schema code."""
 import voluptuous as vol
 
-CONF_SCHEMA = "schema"
+from ..const import CONF_SCHEMA
 
 MQTT_LIGHT_SCHEMA_SCHEMA = vol.Schema(
     {

homeassistant/components/mqtt/vacuum/schema.py

@@ -1,7 +1,8 @@
 """Shared schema code."""
 import voluptuous as vol
 
-CONF_SCHEMA = "schema"
+from ..const import CONF_SCHEMA
+
 LEGACY = "legacy"
 STATE = "state"