Refactor: Move list_of_shapes_to_compound function into compound.py

- The function `list_of_shapes_to_compound` was removed in `pythonocc-core` 7.9.0.
- but occwl depends on it. So we have replaced it with a manual implementation using `BRep_Builder` in:

src/occwl/compound.py

@@ -1,5 +1,7 @@
 from OCC.Core.TopoDS import TopoDS_Compound
-from OCC.Extend.DataExchange import read_step_file, list_of_shapes_to_compound
+from OCC.Extend.DataExchange import read_step_file
+from OCC.Core.BRep import BRep_Builder
+
 from OCC.Core.BRepTools import BRepTools_ShapeSet
 from OCC.Core.STEPControl import STEPControl_Reader
 from OCC.Core.TopAbs import (
@@ -19,6 +21,17 @@ from occwl.base import BottomUpFaceIterator, BottomUpEdgeIterator, BoundingBoxMi
             ShellContainerMixin
 from occwl.shape import Shape
 
+def list_of_shapes_to_compound(shapes):
+    """
+    Combine a list of TopoDS_Shapes into a single TopoDS_Compound.
+    Returns (compound, True) if successful.
+    """
+    builder = BRep_Builder()
+    compound = TopoDS_Compound()
+    builder.MakeCompound(compound)
+    for s in shapes:
+        builder.Add(compound, s)
+    return compound, True
 
 class Compound(Shape, BottomUpFaceIterator, BoundingBoxMixin, BottomUpEdgeIterator,
     EdgeContainerMixin, FaceContainerMixin, SolidContainerMixin, ShellContainerMixin, SurfacePropertiesMixin,