[llvm-branch-commits] [NFC] Fix flakiness in test if run unsharded (PR #112439)

[Vitaly Buka via llvm-branch-commits]

https://github.com/vitalybuka created https://github.com/llvm/llvm-project/pull/112439

If we run all test in a single process, there is high
probability that `99` is already claimed.