[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 3044092 [OpenMP] Replaced mutex lock/unlock in `target` with `std::lock_guard`
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   3044092..44211f2  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 44211f20a82418b20a69df9de6291d923dcbf709.
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!