[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 0f62f05 Revert "[llvm] CMake: Force MSVC to read code as UTF-8"
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   0f62f05..b2fa3b9  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to b2fa3b922ecb219429ec7b839d15a06aedbc955a.
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!