Some images not being imported during the HTML import

Related to https://github.com/laurent22/joplin/issues/11716

The images associated with the to-do list are not being imported to Joplin when using the HTML importer.

[test case multiple html.zip](https://github.com/user-attachments/files/20506644/test.case.multiple.html.zip)

[test case single html_files.zip](https://github.com/user-attachments/files/20506646/test.case.single.html_files.zip)