Fix the issue that iOS 17 indexed PNG workaround breaks the 16bit RGBA PNG

SDWebImage/Core/SDImageIOAnimatedCoder.m

@@ -48,6 +48,10 @@ static CGImageRef __nullable SDCGImageCreateMutableCopy(CGImageRef cg_nullable i
     return newImage;
 }
 
+static inline BOOL SDCGImageIs8Bit(CGImageRef cg_nullable image) {
+    return CGImageGetBitsPerComponent(image) == 8;
+}
+
 static inline CGImageRef __nullable SDCGImageCreateCopy(CGImageRef cg_nullable image) {
     if (!image) return nil;
     return SDCGImageCreateMutableCopy(image, CGImageGetBitmapInfo(image));
@@ -209,6 +213,7 @@ static BOOL SDImageIOPNGPluginBuggyNeedWorkaround(void) {
     // See: #3605 FB13322459
     // ImageIO on iOS 17 (17.0~17.2), there is one serious problem on ImageIO PNG plugin. The decode result for indexed color PNG use the wrong CGImageAlphaInfo
     // The returned CGImageAlphaInfo is alpha last, but the actual bitmap data is premultiplied alpha last, which cause many runtime render bug.
+    // The bug only exists on 8-bits indexed color, not about 16-bits
     // So, we do a hack workaround:
     // 1. Decode a indexed color PNG in runtime
     // 2. If the bitmap is premultiplied alpha, then assume it's buggy
@@ -527,7 +532,7 @@ static BOOL SDImageIOPNGPluginBuggyNeedWorkaround(void) {
     // :)
     CFStringRef uttype = CGImageSourceGetType(source);
     SDImageFormat imageFormat = [NSData sd_imageFormatFromUTType:uttype];
-    if (imageFormat == SDImageFormatPNG && SDImageIOPNGPluginBuggyNeedWorkaround()) {
+    if (imageFormat == SDImageFormatPNG && SDCGImageIs8Bit(imageRef) && SDImageIOPNGPluginBuggyNeedWorkaround()) {
         CGImageRef newImageRef = SDImageIOPNGPluginBuggyCreateWorkaround(imageRef);
         CGImageRelease(imageRef);
         imageRef = newImageRef;