Attempt to display more columns in the "Export Project to Dxf" dialog

[DelazJ]

I don't think this is the most sustainable fix (being able to automatically pass the number of expected columns may be) but it should help fix resurrection of #45441, and avoid hiding the data-defined blocks columns.

That said, I fail to understand why this widget behaves differently to the other ones in which a treeview is involved (let's say the "layer capabilities" or "QGIS Server --> WMTS" in the project properties dialog, ...)

[DelazJ]

No more artifact generation for Windows?

[agiudiceandrea]

No more artifact generation for Windows?

It looks like they are created https://github.com/qgis/QGIS/actions/runs/8685776406?pr=57155 but the automatic comment is no longer added.

[nyalldawson]

I think there's a bug in GitHub itself. The workflows no longer trigger, and there's not even any record of them attempting to run. I was going to give it a couple of weeks and see if it resolves itself... 🤷‍♂️

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[DelazJ]

That said, I fail to understand why this widget behaves differently to the other ones in which a treeview is involved (let's say the "layer capabilities" or "QGIS Server --> WMTS" in the project properties dialog, ...)

Replying to self: the widgets in the ui file of these dialogs DO NOT use QgsLayerTreeView; they use QTreeView. And investigating further, QgsLayerTreeView seems to appear only in "layout legend widget" and "embed layers and groups" ui files. And the particularity of these dialogs is that they show a SINGLE column that takes all the available width.
--> Could it be that QgsLayerTreeView is not meant to display more than one column?
Answering this is beyond my skills so hopefully someone else can give it a look?
I've tried an alternative approach using QTreeview that does not really work. See #57401