Fix T99761: Curves sculpt mode crash with empty curves

The virtual arrays may be null if the curves are empty,
it's simple to just skip the domain interpolation completely.

source/blender/editors/curves/intern/curves_ops.cc

@@ -755,6 +755,9 @@ static int curves_set_selection_domain_exec(bContext *C, wmOperator *op)
 
     CurvesGeometry &curves = CurvesGeometry::wrap(curves_id->geometry);
     bke::MutableAttributeAccessor attributes = curves.attributes_for_write();
+    if (curves.points_num() == 0) {
+      continue;
+    }
 
     if (old_domain == ATTR_DOMAIN_POINT && domain == ATTR_DOMAIN_CURVE) {
       VArray<float> curve_selection = curves.adapt_domain(