ImageIO tvOS xcode13.0 beta3

#ImageIO.framework https://github.com/xamarin/xamarin-macios/pull/12145

diff -ruN /Applications/Xcode_13.0.0-beta2.app/Contents/Developer/Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS.sdk/System/Library/Frameworks/ImageIO.framework/Headers/CGImageProperties.h /Applications/Xcode_13.0.0-beta3.app/Contents/Developer/Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS.sdk/System/Library/Frameworks/ImageIO.framework/Headers/CGImageProperties.h
--- /Applications/Xcode_13.0.0-beta2.app/Contents/Developer/Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS.sdk/System/Library/Frameworks/ImageIO.framework/Headers/CGImageProperties.h	2021-06-17 03:43:44.000000000 -0400
+++ /Applications/Xcode_13.0.0-beta3.app/Contents/Developer/Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS.sdk/System/Library/Frameworks/ImageIO.framework/Headers/CGImageProperties.h	2021-07-13 00:41:30.000000000 -0400
@@ -288,6 +288,7 @@
 IMAGEIO_EXTERN const CFStringRef kCGImagePropertyPNGWarning  IMAGEIO_AVAILABLE_STARTING(10.14, 12.0);
 IMAGEIO_EXTERN const CFStringRef kCGImagePropertyPNGXPixelsPerMeter  IMAGEIO_AVAILABLE_STARTING(10.4, 4.0);
 IMAGEIO_EXTERN const CFStringRef kCGImagePropertyPNGYPixelsPerMeter  IMAGEIO_AVAILABLE_STARTING(10.4, 4.0);
+IMAGEIO_EXTERN const CFStringRef kCGImagePropertyPNGPixelsAspectRatio  IMAGEIO_AVAILABLE_STARTING(12.0, 19.0);
 
 IMAGEIO_EXTERN const CFStringRef kCGImagePropertyAPNGLoopCount  IMAGEIO_AVAILABLE_STARTING(10.10, 8.0);
 IMAGEIO_EXTERN const CFStringRef kCGImagePropertyAPNGDelayTime  IMAGEIO_AVAILABLE_STARTING(10.10, 8.0);