Remove dead code

The considered code was an alternate strategy to define cell-cell
connectivity: through nodes.

src/mesh/Connectivity.hpp

@@ -546,7 +546,6 @@ class Connectivity final : public IConnectivity
   cellToCellGraph() const
   {
     std::vector<std::set<int>> cell_cells(this->numberOfCells());
-    if constexpr (true) {
     const auto& face_to_cell_matrix = this->faceToCellMatrix();
 
     for (FaceId l = 0; l < this->numberOfFaces(); ++l) {
@@ -559,21 +558,6 @@ class Connectivity final : public IConnectivity
         cell_cells[cell_1].insert(cell_0);
       }
     }
-    } else {
-      const auto& node_to_cell_matrix = this->nodeToCellMatrix();
-
-      for (NodeId l = 0; l < this->numberOfNodes(); ++l) {
-        const auto& node_to_cell = node_to_cell_matrix[l];
-        for (size_t i_cell = 0; i_cell < node_to_cell.size(); ++i_cell) {
-          const CellId cell_0 = node_to_cell[i_cell];
-          for (size_t j_cell = 0; j_cell < i_cell; ++j_cell) {
-            const CellId cell_1 = node_to_cell[j_cell];
-            cell_cells[cell_0].insert(cell_1);
-            cell_cells[cell_1].insert(cell_0);
-          }
-        }
-      }
-    }
 
     Array<int> entries(this->numberOfCells() + 1);
     entries[0] = 0;