Hysen hy08acf: use heat_cool for the on position.

This device seems to work in either heating or cooling mode - installation diagrams show hot and cold pipes both connected, but there is no control in the protocol which to use, so assume it is automatically selecting.

custom_components/tuya_local/devices/hysen_hy08acf_thermostat.yaml

@@ -9,7 +9,7 @@ primary_entity:
         - dps_val: false
           value: "off"
         - dps_val: true
-          value: heat
+          value: heat_cool
     - id: 2
       type: integer
       name: temperature