[llvm-branch-commits] [CI] Move CI over to new project computation script (PR #132642)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/132642

This patch migrates the CI over to the new compute_projects.py script
for calculating what projects need to be tested based on a change to
LLVM.