fix: use Uint8Array for diff file writing (#602)

Co-authored-by: Sayali Warule <[email protected]>

comparadise-utils/screenshots.ts

@@ -35,7 +35,7 @@ export function compareScreenshots(screenshotFolder: string) {
     // Create diff.png next to base and new for review
     fs.writeFile(
       createImageFileName(screenshotFolder, 'diff'),
-      PNG.sync.write(diff).toString(),
+      new Uint8Array(PNG.sync.write(diff)),
       err => {
         if (err) {
           console.error('❌ Diff exists but unable to create diff.png', err);