fix: geomdl dependency in conda-forge (#1900)

Co-authored-by: pyansys-ci-bot <92810346+pyansys-ci-bot@users.noreply.github.com>

Author: RobPasMue

doc/changelog.d/1900.fixed.md

@@ -0,0 +1 @@
+geomdl dependency in conda-forge

src/ansys/geometry/core/shapes/curves/nurbs.py

@@ -22,10 +22,9 @@
 """Provides for creating and managing a NURBS curve."""
 
 from functools import cached_property
-from typing import Optional
+from typing import TYPE_CHECKING, Optional
 
 from beartype import beartype as check_input_types
-import geomdl.NURBS as geomdl_nurbs  # noqa: N811
 
 from ansys.geometry.core.math import Matrix44, Point3D
 from ansys.geometry.core.math.vector import Vector3D
@@ -39,6 +38,9 @@
 )
 from ansys.geometry.core.typing import Real
 
+if TYPE_CHECKING:  # pragma: no cover
+    import geomdl.NURBS as geomdl_nurbs  # noqa: N811
+
 
 class NURBSCurve(Curve):
     """Represents a NURBS curve.
@@ -53,14 +55,20 @@ class NURBSCurve(Curve):
 
     """
 
-    def __init__(
-        self,
-    ):
+    def __init__(self):
         """Initialize ``NURBSCurve`` class."""
+        try:
+            import geomdl.NURBS as geomdl_nurbs  # noqa: N811
+        except ImportError as e:  # pragma: no cover
+            raise ImportError(
+                "The `geomdl` library is required to use the NURBSCurve class. "
+                "Please install it using `pip install geomdl`."
+            ) from e
+
         self._nurbs_curve = geomdl_nurbs.Curve()
 
     @property
-    def geomdl_nurbs_curve(self) -> geomdl_nurbs.Curve:
+    def geomdl_nurbs_curve(self) -> "geomdl_nurbs.Curve":
         """Get the underlying NURBS curve.
 
         Notes
@@ -237,7 +245,7 @@ def project_point(
 
         # Function to minimize (distance squared)
         def distance_squared(
-            u: float, geomdl_nurbs_curbe: geomdl_nurbs.Curve, point: np.ndarray
+            u: float, geomdl_nurbs_curbe: "geomdl_nurbs.Curve", point: np.ndarray
         ) -> np.ndarray:
             point_on_curve = np.array(geomdl_nurbs_curbe.evaluate_single(u))
             return np.sum((point_on_curve - point) ** 2)