GradientEffect: Fix incorrect output alpha

Source-Commit: d8ec35fcbacdb80de7891dc0ac3a8ea7c9bf8c8d

Author: Johni0702

unstable/layoutdsl/src/main/kotlin/gg/essential/elementa/effects/GradientEffect.kt

@@ -81,7 +81,7 @@ class GradientEffect(
             vertSource,
             fragSource,
         ).apply {
-            blendState = BlendState.NORMAL
+            blendState = BlendState.ALPHA
             depthTest = URenderPipeline.DepthTest.Always
         }.build()
 
@@ -90,7 +90,7 @@ class GradientEffect(
             UGraphics.DrawMode.QUADS,
             UGraphics.CommonVertexFormats.POSITION_COLOR,
         ).apply {
-            blendState = BlendState.NORMAL
+            blendState = BlendState.ALPHA
             depthTest = URenderPipeline.DepthTest.Always
         }.build()
     }