修复 APNG Truecolour16Alpha 处理器 clone 方法返回类型错误的问题 (#4210)

HMCL/src/main/java/org/jackhuang/hmcl/ui/image/apng/argb8888/Argb8888Processors.java

@@ -453,7 +453,7 @@ public class Argb8888Processors {
 
         @Override
         public Argb8888ScanlineProcessor clone(int bytesPerRow, Argb8888Bitmap bitmap) {
-            return new Truecolour16(bytesPerRow, bitmap);
+            return new Truecolour16Alpha(bytesPerRow, bitmap);
         }
     }