Crash when opening "subcontainer"

FreeCAD crashes immediately, when using one of the Material buttons that start a dialog using ```subcontainer```.
(Import MaterialX file, GPUOpen Material Library, AmbientCG Material Library)
The external client, however starts and is functional.

The corresponding error message in the [log](https://github.com/user-attachments/files/20821627/log.txt) file is

```
Err: /Users/USER/Library/Application Support/FreeCAD/Mod/Render/./Render/subcontainer.py:221: RuntimeWarning: libshiboken: Overflow: Value 5032641280 exceeds limits of type [signed] "i" (4bytes).
self.winid_available.emit(argument)
Err: Err: OverflowErrorErr: Err:
```

This happened on MacOS 15.4 (24E248).