Morento HY4866: standardize timer "off" value

Since adding translations, timer "off" has been standardized to use "cancel",
which is most frequently matching with the tuya value.
This device used "infinite", which has no translation, despite the tuya
value being a capitalised "Cancel".

custom_components/tuya_local/devices/morento_hy4866_wf.yaml

@@ -67,7 +67,7 @@ entities:
         name: option
         mapping:
           - dps_val: Cancel
-            value: infinite
+            value: cancel
           - dps_val: "2H"
             value: "2h"
           - dps_val: "5H"