[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at d8334c4 [flang] Acquire file accessibility, size, positioning
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   d8334c4..675ad1b  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 675ad1bc6a96d3c7ef1909c91695189cd818a143.
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!