[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at fe9a7d9 [RISCV] Use the commercial name for scheduling model (NFC)
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   fe9a7d9..245d71b  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 245d71bae5a9cad472d5ec4cad67a9be0e0d261b.
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!