LibWeb: Fix "stack-use-after-return" in navigate_to_a_fragmement()

Callback running on the session history queue should capture necessary
pointers by value instead of reference, because navigate_to_a_fragment
stack will have been destroyed by the time it will be executed.

Userland/Libraries/LibWeb/HTML/Navigable.cpp

@@ -1095,7 +1095,7 @@ WebIDL::ExceptionOr<void> Navigable::navigate_to_a_fragment(AK::URL const& url,
     auto traversable = traversable_navigable();
 
     // 17. Append the following session history synchronous navigation steps involving navigable to traversable:
-    traversable->append_session_history_traversal_steps([&] {
+    traversable->append_session_history_traversal_steps([this, traversable, history_entry, entry_to_replace] {
         // 1. Finalize a same-document navigation given traversable, navigable, historyEntry, and entryToReplace.
         finalize_a_same_document_navigation(*traversable, *this, history_entry, entry_to_replace);