[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 1596cc8 [NFCI][clang-tidy] FunctionCognitiveComplexityCheck::check(): try to fix windows arm build bots
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   1596cc8..347fd99  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 347fd9955af3fff2622d8349a59974ecc2237ec1.
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!