Remove duplicate code comment in flutter_gallery (#23422)

examples/flutter_gallery/lib/demo/animation/home.dart

diff --git a/examples/flutter_gallery/lib/demo/animation/home.dart b/examples/flutter_gallery/lib/demo/animation/home.dart
index 6f3d9e4..ae7a34e 100644
--- a/examples/flutter_gallery/lib/demo/animation/home.dart
+++ b/examples/flutter_gallery/lib/demo/animation/home.dart
@@ -292,9 +292,6 @@
     // The layout's progress from from a column to a row. Its value is
     // 0.0 when size.height equals the maxHeight, 1.0 when the size.height
     // equals the midHeight.
-    // The layout's progress from from a column to a row. Its value is
-    // 0.0 when size.height equals the maxHeight, 1.0 when the size.height
-    // equals the midHeight.
     final double tColumnToRow =
       1.0 - ((size.height - midHeight) /
              (maxHeight - midHeight)).clamp(0.0, 1.0);