GdImage cannot serialize in PHP8.1

If there is custom code you must provide it in a bug report so that the community can reproduce the bug.

I just run the resize functional provieded from Batch Image Resize module without any custom code.
I do some modify to confirm that this issue is most related core instead of Batch Image Resize, and can confirm the module can work on PHP 7.4 environment.

Please explain in some detail why this is a Drupal core bug based on your research.

Add to the issue summary steps to reproduce the bug that contributors can follow.

At first, the Batch Resize Image module do very simple thing which is call Image::resize method to resize image assets, and I have tried to set breakpoint to confirm the error message happened when $image->resize() runs.

        if ($file->filesize > $threshold_size && ($width > $size_limit || $height > $size_limit)) {
          // Computing the new height and width based on user input.
          if ($width > $height) {
            $width = $size_limit;
            $height = $height * $width / $width;
          }
          else {
            $height = $size_limit;
            $width = $width * $height / $height;
          }

          // Updating the image size as per set threshold.
          $image->resize($width, $height);
          $image->save();

          // Chnaging the image size in the database.
          $file_entity = \Drupal::entityTypeManager()->getStorage('file')->load($file->fid);
          $file_entity->save();
          $result['message'] = '"' . $file->filename . "\" has been transformed.";
          $context['results']['resized'][] = $result;
        }

Ref: BatchResizeImageForm.php L102:L122

And then, I have tried to modify to use $image->scale() and other methods to validate but get same error.
Therefore, I use alternative similar module Image Compression → to confirm and got the same result, it also faced the issue which can not serialized GdImage object.

Finally I decide to switch PHP version to 7.4 and then the module works, so that I guess this issue most related Drupal core.

Without the contrib module is this reproducible in core. Sounds like all tests and examples involve using a contrib module that is failing.