[gn build] Port 23c7328

Author: llvmgnsyncbot

llvm/utils/gn/secondary/libcxx/include/BUILD.gn

@@ -174,6 +174,7 @@ if (current_toolchain == default_toolchain) {
       "__algorithm/ranges_move.h",
       "__algorithm/ranges_move_backward.h",
       "__algorithm/ranges_none_of.h",
+      "__algorithm/ranges_nth_element.h",
       "__algorithm/ranges_remove.h",
       "__algorithm/ranges_remove_if.h",
       "__algorithm/ranges_replace.h",