[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at f164534 Add a `dialect_registration` callback for "translations" registered with mlir-translate
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   f164534..5238193  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 52381938bcc8547316d79a4721281da7f934d9b8.
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!