[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 35bee35 [clang-tidy] prevent generated checks from triggering assertions on anonymous functions
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   35bee35..b97e402  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to b97e402ca5ba3d1a4795ed61f8cb36783b00ed44.
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!