[compiler-rt] [TEST][Darwin] Change x86_64h UNSUPPORTED lit feature used in san cov test (PR #93706)

[Mariusz Borsa via llvm-commits]

wrotki wrote:

LGTM. Verified the fix on my x86 Mac, it shows UNSUPPORTED for SanitizerCommon-lsan-x86_64h-Darwin as intended

https://github.com/llvm/llvm-project/pull/93706