[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 86fc193 [lldb] Don't pass --rerun-all-issues on Windows.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   86fc193..f91d18e  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to f91d18eaa946b2d2ea5a9334fb099c3e409ad2d1.
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!