yet another fix

Author: lrvideckis

library/graphs/bridges_cuts/bridge_tree.hpp

@@ -4,8 +4,7 @@
 //!   {
 //!     vector<vector<pii>> adj(n);
 //!     auto [num_ccs, br_id, is_br] = bridges(adj, m);
-//!     vector<vi> bt = bridge_tree(adj,
-//!       num_ccs, br_id, is_br);
+//!     auto bt = bridge_tree(adj, num_ccs, br_id, is_br);
 //!   }
 //!   vector<basic_string<array<int, 2>>> adj(n);
 //!   auto [num_ccs, br_id, is_br] = bridges(adj, m);