ci: OpenBSD / Tests (unix) intermittent failure

[xtqqczze]

errors like:

error: extern location for rustc_hash does not exist: /home/runner/work/coreutils/coreutils/target/debug/deps/librustc_hash-ec58a219f6debe03.rmeta

https://github.com/uutils/coreutils/actions/runs/26074052345/job/76661265350?pr=12375