Corrected erroneous edit to fill description to -> None

Author: kmatch98

shared-bindings/displayio/Bitmap.c

@@ -273,7 +273,7 @@ STATIC mp_obj_t displayio_bitmap_obj_blit(size_t n_args, const mp_obj_t *pos_arg
 MP_DEFINE_CONST_FUN_OBJ_KW(displayio_bitmap_blit_obj, 4, displayio_bitmap_obj_blit);
 // `displayio_bitmap_obj_blit` requires at least 4 arguments
 
-//|     def fill(self, value: Any) -> Any:
+//|     def fill(self, value: Any) -> None:
 //|         """Fills the bitmap with the supplied palette index value."""
 //|         ...
 //|