LibWeb: Remove unused headers in StructuredSerialize.cpp

Userland/Libraries/LibWeb/HTML/StructuredSerialize.cpp

@@ -6,13 +6,11 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <AK/HashTable.h>
 #include <AK/StdLibExtras.h>
 #include <AK/String.h>
 #include <AK/Vector.h>
 #include <LibJS/Forward.h>
 #include <LibJS/Runtime/BigInt.h>
-#include <LibJS/Runtime/BigIntObject.h>
 #include <LibJS/Runtime/BooleanObject.h>
 #include <LibJS/Runtime/Date.h>
 #include <LibJS/Runtime/NumberObject.h>