Fix #4837. Make mathutils dependency optional.

In the long term, I'd like to replace mathutils with numpy.

src/ifcopenshell-python/ifcopenshell/util/shape_builder.py

@@ -25,7 +25,7 @@ import ifcopenshell.api
 import ifcopenshell.util.element
 import ifcopenshell.util.representation
 import ifcopenshell.util.unit
-from math import cos, sin, pi, tan, radians, degrees, atan, sqrt, ceil
+from math import cos, sin, pi, tan, radians, degrees, atan, sqrt
 from typing import Union, Optional, Literal, Any, Sequence
 from itertools import chain
 from mathutils import Vector, Matrix

src/ifcopenshell-python/pyproject.toml

@@ -15,7 +15,11 @@ classifiers = [
     "Programming Language :: Python :: 3",
     "License :: OSI Approved :: GNU Lesser General Public License v3 or later (LGPLv3+)",
 ]
-dependencies = ["mathutils", "shapely", "numpy", "isodate", "python-dateutil", "lark"]
+dependencies = ["shapely", "numpy", "isodate", "python-dateutil", "lark"]
+
+[project.optional-dependencies]
+geometry = ["mathutils"]
+dev = ["pytest"]
 
 [project.urls]
 "Homepage" = "http://ifcopenshell.org"