Fix: Mesh boolean redundant transfer of edge attributes

In 157e7e0351 edge calculation was updated to
propagate attributes, but the manifold boolean propagates
edge attributes itself. It seems this causes some issues where
boolean attributes get invalid values, which I discovered while
developing #148063. I didn't investigate too deeply because
I'm going to have to restructure this code for #122398 anyway.

Pull Request: https://projects.blender.org/blender/blender/pulls/148096

source/blender/geometry/intern/mesh_boolean.cc

@@ -799,6 +799,19 @@ static Mesh *imesh_to_mesh(meshintersect::IMesh *im, MeshesToIMeshInfo &mim)
   }
   dst_material_indices.finish();
 
+  /* Remove edge attributes so they're not processed by #mesh_calc_edges. They are propagated
+   * separately afterwards, and yet they exist because #BKE_mesh_new_nomain_from_template created
+   * them. */
+  Set<std::string> edge_attributes;
+  result->attributes().foreach_attribute([&](const bke::AttributeIter &iter) {
+    if (iter.domain == bke::AttrDomain::Edge) {
+      edge_attributes.add(iter.name);
+    }
+  });
+  for (const StringRef attribute : edge_attributes) {
+    result->attributes_for_write().remove(attribute);
+  }
+
   bke::mesh_calc_edges(*result, false, false);
   merge_edge_customdata_layers(result, mim);