Bulk operation not working on nodes.

Patch to solve the issue.

How to reproduce

In our case the issue gets reproduced:

1. We install module views_bulk_edit
2. Go to content view
3. Add field "Content: Node operations bulk form" in the view
4. Enable operation "Edit content"
5. Go to Content types
6. In any content type add a field of type 'Text (plain)' and enable 'Unique' feature
7. Create several nodes of the content type that has that field marked as unique
8. Go to Content view
9. Select 2-3 nodes, select operation 'Edit content' and click on 'Apply to selected items'
10. Select any field and change its value
11. Click on 'Confirm' button and the error will reproduce

At this point, going to Reports > Recent log pages will show the error described by @selvira in this ticket's summary.

Patch testing

When adding the patch to the composer.json and re-running composer install will make the patch being applied. Repeat the steps mentioned above and the issue is not happening.

Thanks @abel,
Ready to be merged then.

Greetings.