[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 7c026a8 [SystemZ] Define MaxInstLength to have the value of 6.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   7c026a8..1a7a9efe master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 1a7a9efec3cf872dcf3e1a6e6fe39e797c4d9fc6.
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!