PartDesign: Linear pattern crashes on high count

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Problem description

If repeat count is obviously too high, it freezes very long and crashes. It would be great to have an alert instead of trying to do something that will most likely break.

### Full version info

```shell
OS: Arch Linux (KDE/plasma/wayland)
Architecture: x86_64
Version: 1.1.0dev.42942 (Git) AppImage
Build date: 2025/08/15 15:09:23
Build type: Release
Branch: main
Hash: af83b6883eb0afae7d82aaaefc6a3991429c0a70
Python 3.11.13, Qt 6.8.3, Coin 4.0.3, Vtk 9.3.1, boost 1_86, Eigen3 3.4.0, PySide 6.8.3
shiboken 6.8.3, xerces-c 3.2.5, IfcOpenShell 0.8.2, OCC 7.8.1
Locale: French/France (fr_FR)
Navigation Style/Orbit Style/Rotation Mode: CAD/Rounded Arcball/Window center
Stylesheet/Theme/QtStyle: FreeCAD Dark.qss/FreeCAD Dark/
Logical DPI/Physical DPI/Pixel Ratio: 96/93.1131/1.5
Installed mods:
* BillOfMaterials 1.0.3.3
* fasteners 0.5.39
* FreeCAD-Ribbon 1.9.1.8
* SaveAndRestore 0.2.1
* SearchBar 1.4.2
```

### Subproject(s) affected?

None

### Anything else?

It append to me putting by mistake the length (10000) into the repeat count, but I think a mistake should not crash the app.

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct