Light: don't change effect if it is the same as current effect.

When scenes are used, the effect always comes with it. In many cases, the
effect is "off", which matches multiple color modes. Avoid changes to the
color mode as a side effect of this HA scene behaviour.

Issue #3086

custom_components/tuya_local/light.py

@@ -412,7 +412,7 @@ class TuyaLocalLight(TuyaLocalEntity, LightEntity):
                 }
             elif not self._effect_dps:
                 effect = params.get(ATTR_EFFECT)
-                if effect:
+                if effect and effect != self.effect:
                     if effect == EFFECT_OFF:
                         # Turn off the effect. Ideally this should keep the
                         # previous mode, but since the mode is shared with