[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at e0dc3db [mlir][Linalg] NFC - Cleanup explicitly instantiated paterns 1/n - LinalgToStandard.cpp
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   e0dc3db..c11c20f  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to c11c20fb0036bc8f69b2028422f050ee66acbb64.
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!