[light] Fix LightControlAction trigger args with reference types

`const Ts &...` is ill-formed when Ts is already a reference (e.g. a
trigger that passes `std::string &`). Forward Ts by-value so the
generated lambda matches ApplyFn for any valid trigger arg type.

tests/components/light/common.yaml

@@ -127,6 +127,21 @@ esphome:
           blue: 0%
           transition_length: 1s
 
+# Exercise light actions inside a trigger with non-empty Ts (number on_value
+# passes float).
+number:
+  - platform: template
+    id: test_number_brightness
+    optimistic: true
+    min_value: 0
+    max_value: 100
+    step: 1
+    on_value:
+      then:
+        - light.turn_on:
+            id: test_monochromatic_light
+            brightness: !lambda "return x / 100.0;"
+
 light:
   - platform: binary
     id: test_binary_light