[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at d761e45 Fix more build failures caused by f4257c5832aa51e960e7351929ca3d37031985b7
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   d761e45..bfc7636  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to bfc76366125b846bfdfac5cc19c356542a399e45.
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!