fix: image uploader bg in light mode (#8385)

packages/editor/src/core/extensions/custom-image/components/block.tsx

@@ -234,7 +234,7 @@ export function CustomImageBlock(props: CustomImageBlockProps) {
         }}
       >
         {showImageLoader && (
-          <div className="animate-pulse bg-layer-2 rounded-md" style={{ width: size.width, height: size.height }} />
+          <div className="animate-pulse bg-layer-1 rounded-md" style={{ width: size.width, height: size.height }} />
         )}
         <img
           ref={imageRef}