Standalone equations are partially confused with regular text items

### Bug
The layout detector wrongly classifies some obvious equations as text items. The post-processing needs to be improved to resolve these cases better when there are competing proposals on the same element with different labels and confidences.

### Steps to reproduce

Convert the provided example PDF and observe missed formulas.
[code_and_formulas_2.pdf](https://github.com/user-attachments/files/18394756/code_and_formulas_2.pdf)

### Docling version

```

Docling version: 2.15.1
Docling Core version: 2.14.0
Docling IBM Models version: 3.1.2
Docling Parse version: 3.0.0
```
### Python version
Any