This repo is provided by them with the commit prior to when it was
compromised. LLVM has switched to the same repo for now.
We probably want to find some better solution to this at some point.
Sometimes github or the CI runner times out trying to checkout the
source and stays timing out forever.
Give it a three minute timeout otherwise the CI runner will stall
forever.
Adapted from LLVM version of pr-code-format.yml.
Copies a few scripts from LLVM to External/.
Runs self-hosted on X64.
Assumes clang-format 16.0.6 for formatting.
Paulo Matos