[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 4c30d4b [NFC][StackSafety] Change map key comparison
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   4c30d4b..d28f672  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to d28f67292e04bde4b91146c342d27f989eeb5020.
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!