[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 98031b6 [polly] Fix -Wunused-lambda-capture and -Wunused-variable
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   98031b6..a95b25b  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to a95b25b29ecf498afa17ad526226ae3a4271d228.
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!