[gn build] Port 3dcdb4c

Author: llvmgnsyncbot

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

@@ -1216,7 +1216,6 @@ if (current_toolchain == default_toolchain) {
       "__mdspan/mdspan.h",
       "__memory/addressof.h",
       "__memory/align.h",
-      "__memory/aligned_alloc.h",
       "__memory/allocate_at_least.h",
       "__memory/allocation_guard.h",
       "__memory/allocator.h",