[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at ec1445c [X86] Fix for ballooning compile times due to Load Value Injection (LVI) mitigations
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   ec1445c..0f10165  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 0f1016562648e0c5ab0618823d5d6b7280ca86ba.
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!