Compilation with std=c++23

[fanquake]

In file included from leveldb/util/comparator.cc:14:
./leveldb/util/no_destructor.h:40:17: error: 'aligned_storage<8, 8>' is deprecated [-Werror,-Wdeprecated-declarations]
   40 |   typename std::aligned_storage<sizeof(InstanceType),
      |                 ^
leveldb/util/comparator.cc:71:47: note: in instantiation of template class 'leveldb::NoDestructor<leveldb::(anonymous namespace)::BytewiseComparatorImpl>' requested here
   71 |   static NoDestructor<BytewiseComparatorImpl> singleton;
      |                                               ^
/usr/lib/llvm-18/bin/../include/c++/v1/__type_traits/aligned_storage.h:90:8: note: 'aligned_storage<8, 8>' has been explicitly marked deprecated here
   90 | struct _LIBCPP_DEPRECATED_IN_CXX23 _LIBCPP_TEMPLATE_VIS aligned_storage {
      |        ^
/usr/lib/llvm-18/bin/../include/c++/v1/__config:1013:41: note: expanded from macro '_LIBCPP_DEPRECATED_IN_CXX23'
 1013 | #    define _LIBCPP_DEPRECATED_IN_CXX23 _LIBCPP_DEPRECATED
      |                                         ^
/usr/lib/llvm-18/bin/../include/c++/v1/__config:974:49: note: expanded from macro '_LIBCPP_DEPRECATED'
  974 | #      define _LIBCPP_DEPRECATED __attribute__((__deprecated__))
      |                                                 ^

See google#896 & google#1013.