Refactor ref callbacks for LinearGradient and Texture

Updated ref callback functions to use explicit if statements for setting refs in LinearGradient and Texture components. This improves readability and consistency in the Scene component.

Author: jonobr1

src/Playground.tsx

@@ -308,7 +308,9 @@ function Scene() {
       {/* Linear Gradient Example */}
       <Group x={cellWidth * 1.5} y={cellHeight * 3.5}>
         <LinearGradient
-          ref={(ref) => ref && setLinearGradient(ref)}
+          ref={(ref) => {
+            if (ref) setLinearGradient(ref);
+          }}
           x1={0}
           y1={0}
           x2={1}
@@ -347,7 +349,9 @@ function Scene() {
       {/* Texture Example */}
       <Group x={cellWidth * 3.5} y={cellHeight * 3.5}>
         <Texture
-          ref={(ref) => ref && setTexture(ref)}
+          ref={(ref) => {
+            if (ref) setTexture(ref);
+          }}
           src="https://placehold.co/60x60/9B59B6/FFFFFF?text=TEX"
         />
         <Rectangle