[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 6d0be74 llvm-dwarfdump: Don't try to parse rnglist tables when dumping CUs
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   6d0be74..b180261  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to b18026114ab1410d531559ad6d9f1b445b98a35f.
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!