[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at db6f7e0 [git-clang-format] Process CUDA header files
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   db6f7e0..8fb73ce  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 8fb73cecfd1a1c0367759721566a91d320f76d8b.
CMake Error at CMakeLists.txt:3 (cmake_minimum_required):
  CMake 3.13.4 or higher is required.  You are running version 3.7.1


-- Configuring incomplete, errors occurred!