Modify heatpump configs to use heat_cool instead of auto in hvac_mode.

According to comments in HA climate/const.py, auto is for temperature set by
a schedule, AI or other non-user controlled mechanism.  What most heatpumps
have labelled as "Auto" is called heat_cool (set a temperature, and the heatpump
switches between heating and cooling automatically depending on what is needed).

custom_components/tuya_local/devices/electriq_12wminv_heatpump.yaml

@@ -69,7 +69,7 @@ primary_entity:
             - dps_val: false
               value_redirect: power
             - dps_val: true
-              value: auto
+              value: heat_cool
     - id: 5
       name: fan_mode
       type: integer

custom_components/tuya_local/devices/hellnar_heatpump.yaml

@@ -49,7 +49,7 @@ primary_entity:
             - dps_val: false
               value_redirect: power
             - dps_val: true
-              value: auto
+              value: heat_cool
         - dps_val: cold
           icon: "mdi:snowflake"
           icon_priority: 2