Simplify world background mode handling in src/document/world-settings.ts

src/document/world-settings.ts

@@ -195,18 +195,4 @@ export function changeWorldBackgroundMode(
     topColorHex: DEFAULT_GRADIENT_TOP_COLOR,
     bottomColorHex: DEFAULT_GRADIENT_BOTTOM_COLOR
   };
-}
-    }
-
-    return {
-      mode: "image",
-      assetId: imageAssetId
-    };
-  }
-
-  return {
-    mode: "verticalGradient",
-    topColorHex: background.mode === "solid" ? background.colorHex : background.topColorHex,
-    bottomColorHex: DEFAULT_GRADIENT_BOTTOM_COLOR
-  };
 }