[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at ad865d9 [lldb-vscode] Allow an empty 'breakpoints' field to clear breakpoints.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   ad865d9..e9b3884  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to e9b38841619f20a6f4c8657880fd487083ba499a.
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!