fixed avifDecoder memory leak

Author: acefsm

SDWebImageAVIFCoder/Classes/SDImageAVIFCoder.m

@@ -131,6 +131,7 @@ - (UIImage *)decodedImageWithData:(NSData *)data options:(SDImageCoderOptions *)
         UIImage *image = [[UIImage alloc] initWithCGImage:imageRef scale:scale orientation:UIImageOrientationUp];
     #endif
         CGImageRelease(imageRef);
+        avifDecoderDestroy(decoder);
         return image;
     }