fix: Call codec.dispose in dev/ (#161112)

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PR derived from flutter/flutter#159945.

Added `codec.dispose()` for directories under `dev/`.

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Author: koji-1009

dev/benchmarks/macrobenchmarks/lib/src/draw_atlas.dart

@@ -10,6 +10,7 @@ Future<ui.Image> loadImage(String asset) async {
   final ui.ImmutableBuffer buffer = await ui.ImmutableBuffer.fromAsset(asset);
   final ui.Codec codec = await PaintingBinding.instance.instantiateImageCodecWithSize(buffer);
   final ui.FrameInfo frameInfo = await codec.getNextFrame();
+  codec.dispose();
   return frameInfo.image;
 }
 

dev/benchmarks/macrobenchmarks/lib/src/draw_vertices.dart

@@ -10,6 +10,7 @@ Future<ui.Image> loadImage(String asset) async {
   final ui.ImmutableBuffer buffer = await ui.ImmutableBuffer.fromAsset(asset);
   final ui.Codec codec = await PaintingBinding.instance.instantiateImageCodecWithSize(buffer);
   final ui.FrameInfo frameInfo = await codec.getNextFrame();
+  codec.dispose();
   return frameInfo.image;
 }
 

dev/integration_tests/wide_gamut_test/lib/main.dart

@@ -238,7 +238,9 @@ Future<ui.Image> _loadImage() async {
   );
   final ui.ImageDescriptor descriptor = await ui.ImageDescriptor.encoded(buffer);
   final ui.Codec codec = await descriptor.instantiateCodec();
-  return (await codec.getNextFrame()).image;
+  final ui.FrameInfo frameInfo = await codec.getNextFrame();
+  codec.dispose();
+  return frameInfo.image;
 }
 
 class MyHomePage extends StatefulWidget {