Admin file upload with `blank=True` fails due to a missing file

[herrbenesch]

Hey there, thank you for this useful project.

I'm using
django ==5.0.3
django-s3file ==5.5.5
django-storages ==1.14.2

I'm using django-pictures with django-s3file to serve and store my images.
I have a model field setup like so

    image = PictureField(
        _("image"),
        upload_to=FilePattern(
            filename_pattern=("fancy-pattern),
        ),
        aspect_ratios=["1/1"],
        storage=some_s3_storage,
        blank=True,
        file_types=["WEBP", "JPEG"],
        width_field="image_width",
        height_field="image_height",
    )

Now if I try to save an instance of the model in the admin, I'm getting the following error message:

TypeError: object null is not iterable (cannot read property Symbol(Symbol.iterator))
  at Function.from(<anonymous>)
  at uploadFiles(/static/s3file/js/s3file.min.7bb6c3f3de1e.js:1:164)
  at ? (/static/s3file/js/s3file.min.7bb6c3f3de1e.js:1:2879)
  at Array.forEach(<anonymous>)
  at uploadS3Inputs(/static/s3file/js/s3file.min.7bb6c3f3de1e.js:1:2835)
  at HTMLFormElement.<anonymous>(/static/s3file/js/s3file.min.7bb6c3f3de1e.js:1:3350)

If I remove blank=True from the model definition, the upload works without a problem.
Do you have an idea what is wrong here?