[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 32ae37b [clang-tidy] Fix dynamic build failures after 156b127945a8c923d141e608b7380427da024376
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   32ae37b..c81dd3d  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to c81dd3d159ab03d46e4280c458d3c29e56648218.
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!