[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at f721212 [SVE] Don't reorder subvector/binop sequences when the resulting binop is not legal.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   f721212..8a3907c  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 8a3907cd494e8779bbc16ec5cfc763289b0ce041.
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!