Avoid panic on non-UTF filenames in statetest runner

[prestoalvarez]

Description

• Summary: Replace unsafe file_name().unwrap().to_str().unwrap() with a safe check in skip_test to prevent panics on non-UTF or missing filenames.
• Change: In bins/revme/src/cmd/statetest/runner.rs, use and_then(|s| s.to_str()) with early return (false) if the name is invalid. Added a brief comment.
• Rationale: CLI should not crash on valid Unix paths with non-UTF names; default behavior is to not skip when the filename is unknown.

[codspeed-hq]

CodSpeed Performance Report

Merging #2948 will not alter performance

_{Comparing prestoalvarez:main (2e62120) with main (36cae77)}

Summary

✅ 173 untouched benchmarks