Rename deprecated light rgb_order to channel_colors

ESPHome renamed the esp32_rmt_led_strip platform's rgb_order option to
channel_colors; update the remaining devices using it.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

mcu-apollo-dev.yaml

@@ -50,7 +50,7 @@ light:
     id: rgb_leds
     chipset: WS2812
     num_leds: 10
-    rgb_order: GRB
+    channel_colors: GRB
     rmt_symbols: 48
     effects:
       # Use default parameters:
@@ -77,7 +77,7 @@ light:
     id: onboard_rgb_led
     chipset: WS2812
     num_leds: 1
-    rgb_order: GRB
+    channel_colors: GRB
     rmt_symbols: 48
 
 output: