fix(Field.Upload): async fileHandler and onFileDelete should work in Iterate.Array

[tujoworker]

Motivation: https://dnb-it.slack.com/archives/CMXABCHEY/p1769766155450729
Closes #6156

Deploy preview: https://fix-upload-in-iterate.eufemia-e25.pages.dev/uilib/extensions/forms/feature-fields/more-fields/Upload/demos/#with-iteratearray

[github-actions]

Branch Preview URL (stable):
https://fix-upload-in-iterate.eufemia-e25.pages.dev

https://fix-upload-in-iterate.eufemia-e25.pages.dev

Deployment URL (unique):
https://c35248b7.eufemia-e25.pages.dev

https://c35248b7.eufemia-e25.pages.dev

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

[langz]

I've added a commit containing an example, so that it will be easier to validate in the deploy preview, if the fix works as expected or not.

[langz]

Note to self it should work with both Form.Handler with data/defaultData and also with Iterate.Array value.
Form.Handler is most important as that's the use case that's been reported.

[pkg-pr-new]

• eufemia-starter

  yarn add https://pkg.pr.new/dnbexperience/eufemia/@dnb/eufemia@6684.tgz
  

commit: 9a49929

[langz]

I did a quick test locally, using the stories, but I was still able to experience the same issue as reported:

Screen.Recording.2026-02-18.at.12.56.40.mov

[tujoworker]

I did a quick test locally, using the stories, but I was still able to experience the same issue as reported:

Nice findings! A new test that fails with the old implementation is added. Also, the fix for this specific issue is inside Iterate.Array.

[langz]

I did a quick test locally, using the stories, but I was still able to experience the same issue as reported:

Nice findings! A new test that fails with the old implementation is added. Also, the fix for this specific issue is inside Iterate.Array.

I've tested quite many scenarios and this fix seems to work great 👍
Thanks so much ❤️
Myself and AI was stuck with thinking the fix would be in Upload and/or Field.Upload (#6156) 😓 😂

[langz]

Note to self it should work with both Form.Handler with data/defaultData and also with Iterate.Array value. Form.Handler is most important as that's the use case that's been reported.

I’ve not tested both scenarios yet. But only the main scenario.