fix text shadow issue

com.unity.uiwidgets/Runtime/painting/text_style.cs

         public readonly float? height;
         public readonly bool inherit;
         public readonly float? letterSpacing;
-        public readonly List<BoxShadow> shadows;
+        public readonly List<Shadow> shadows;
         public readonly TextBaseline? textBaseline;
         public readonly float? wordSpacing;
 
             float? decorationThickness = null,
             string fontFamily = null,
             List<string> fontFamilyFallback = null,
-            List<BoxShadow> shadows = null,
+            List<Shadow> shadows = null,
             List<FontFeature> fontFeatures = null,
             string debugLabel = null) {
             D.assert(color == null || foreground == null, () => _kColorForegroundWarning);
             float decorationThicknessDelta = 0.0f,
             string fontFamily = null,
             List<string> fontFamilyFallback = null,
-            List<BoxShadow> shadows = null,
+            List<Shadow> shadows = null,
             float fontSizeFactor = 1.0f,
             float fontSizeDelta = 0.0f,
             int fontWeightDelta = 0,
             Color decorationColor = null,
             TextDecorationStyle? decorationStyle = null,
             float? decorationThickness = null,
-            List<BoxShadow> shadows = null,
+            List<Shadow> shadows = null,
             List<FontFeature> fontFeatures = null,
             string debugLabel = null) {
             D.assert(color == null || foreground == null, () => _kColorForegroundWarning);
                     ? new Paint {color = backgroundColor}
                     : null
                 ),
-                shadows: shadows?.Cast<Shadow>().ToList(),
+                shadows: shadows?.ToList(),
                 fontFeatures: fontFeatures
             );
         }