[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 44d65ef Fix includes in llvm/Support/FileSystem/UniqueID.h after 23ed570af1cc165afea1b70a533a4a39d6656501
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   44d65ef..7942960  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 794296019966901a1d244c1012641dc8bf8d0b8f.
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!