[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at d6fadc4 [gcov] Process .gcda immediately after the accompanying .gcno instead of doing all .gcda after all .gcno
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   d6fadc4..c2f8bc9  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to c2f8bc986fb39f6a72aafd5dd0d31ec29ad8ce9b.
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!