add todo comment about changing pixel_shader when support for CP6 is dropped

Author: FoamyGuy

adafruit_displayio_layout/widgets/icon_widget.py

@@ -60,7 +60,10 @@ def __init__(self, label_text, icon, on_disk=False, **kwargs):
             self._file = open(self._icon, "rb")
             image = OnDiskBitmap(self._file)
             tile_grid = TileGrid(
-                image, pixel_shader=getattr(image, "pixel_shader", ColorConverter())
+                image,
+                pixel_shader=getattr(image, "pixel_shader", ColorConverter())
+                # TODO: Once CP6 is no longer supported replace the above line with below.
+                # tile_grid = TileGrid(image, pixel_shader=image.pixel_shader)
             )
         else:
             image, palette = adafruit_imageload.load(icon)