[gn build] Port 05f88b1

Author: llvmgnsyncbot

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

@@ -802,7 +802,6 @@ if (current_toolchain == default_toolchain) {
       "__type_traits/aligned_storage.h",
       "__type_traits/aligned_union.h",
       "__type_traits/alignment_of.h",
-      "__type_traits/apply_cv.h",
       "__type_traits/can_extract_key.h",
       "__type_traits/common_reference.h",
       "__type_traits/common_type.h",