Core: Refine doesn't work for padded Spline edges

### Problem description

As seen on the picture, when padding a face that contains spline, the unnecessary edge doesn't get removed (refined).

File: [SplinePadRefine.zip](https://github.com/user-attachments/files/24913470/SplinePadRefine.zip)

Notes:
- Could be related to #13217.
- Another example with gears:

### Workbench affected?

Part Design

### Steps to reproduce

1. Make sketch with a B-Spline
2. Pad the sketch
3. Pad the face of the body

### Expected behavior

No unnecessary edges.

### Actual behavior

Edge is visible for the spline shape

### Development version About Info (in Safe Mode)

```shell
OS: Windows 11 build 22631
Architecture: x86_64
Version: 1.2.0dev.20260120 (Git shallow)
Build date: 2026/01/20 21:54:07
Build type: Release
Branch: (HEAD detached at 9beca43)
Hash: 9beca4363ad327e453ee5a27f737537e31467901
Python 3.11.14, 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 3.3.0, IfcOpenShell 0.8.2, OCC 7.8.1
Locale: English/United Kingdom (en_GB)
Navigation Style/Orbit Style/Rotation Mode: Revit/Trackball/Window center
Stylesheet/Theme/QtStyle: FreeCAD.qss/FreeCAD Dark/
Logical DPI/Physical DPI/Pixel Ratio: 96/102.243/1.5
Installed mods:
* 3D_Printing_Tools
* CubeMenu (Disabled)
* Defeaturing 1.2.6
* fasteners 0.5.41
* freecad.gears 1.3.0
* kicadStepUpMod 11.7.3
* Launcher
* ModernUI (Disabled)
* OpenTheme 2025.5.20
* PieMenu 1.12.0
* POV-Ray-Rendering
* ToolbarStyle
* WebTools 1.0.0
```

### Last known good version (optional)

```shell

```