[Bug]: Adding children nodes doesn't work for operators

[vmalyk]

Expected behavior

Operators should be have possibility adding children and adding more as 1 operator.

Actual behavior

If drag'n'drop node to operator field - nothing happened and you have option adding nodes to parent only.

Looks like fieldConfigDialog has alot of changes in Admin UI regarding how it handles in ExtJS and no these changes in Datahub version.
Additionally, as you see - no way adding more as 1 operator to schema - looks like reason is the same.

Steps to reproduce

Reproduced on demo in attached video:
https://github.com/user-attachments/assets/455d274a-4440-40fc-8954-641209640047

[github-actions]

Thanks a lot for reporting the issue. We did not consider the issue as "Pimcore:Priority", "Pimcore:ToDo" or "Pimcore:Backlog", so we're not going to work on that anytime soon. Please create a pull request to fix the issue if this is a bug report. We'll then review it as quickly as possible. If you're interested in contributing a feature, please contact us first here before creating a pull request. We'll then decide whether we'd accept it or not. Thanks for your understanding.