fix (vt_14n1_airquality): use correct scale for H2CO and TVOC

Was off by one decimal place due to misreading of mg on screen vs more
natural μg reported by device.

custom_components/tuya_local/devices/vt_14n1_airquality.yaml

@@ -59,8 +59,6 @@ entities:
         name: sensor
         unit: ugm3
         class: measurement
-        mapping:
-          - scale: 0.1
   - entity: sensor
     class: volatile_organic_compounds
     dps:
@@ -69,8 +67,6 @@ entities:
         name: sensor
         unit: ugm3
         class: measurement
-        mapping:
-          - scale: 0.1
   - entity: sensor
     class: pm25
     dps: