Update/retrain layout model to identify correctly single column reference pages

[PeterStaar-IBM]

Bug

Currently, I see that the layout model makes sometimes tables out of references.

Steps to reproduce

example 1: https://arxiv.org/pdf/2106.09685

example 2: https://arxiv.org/pdf/2501.12948

Docling version

Docling version: 2.18.0
Docling Core version: 2.17.1
Docling IBM Models version: 3.3.0
Docling Parse version: 3.2.0
Python: cpython-312 (3.12.6)
Platform: macOS-15.3-arm64-arm-64bit

[cau-git]

see docling-project/docling-ibm-models#92