[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at d784f74 [NFC][Asan] Remove unused macro
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   d784f74..6bf25f4  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 6bf25f45a9b6bd2bf6bd4bf03f6b0d0e2839c33f.
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!