[llvm] [NFC] test/lit.cfg.py formatting (PR #151218)

[Mircea Trofin via llvm-commits]

mtrofin wrote:

### Merge activity

* **Aug 1, 5:19 AM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/151218).


https://github.com/llvm/llvm-project/pull/151218