fix: stream molecule subprocess output to CI logs

run_molecule_parallel.py was capturing stdout/stderr, which hid the
actual molecule failure details from CI logs. Inherit the parent
stdout/stderr instead so failures are visible for debugging.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

scripts/run_molecule_parallel.py

@@ -49,8 +49,6 @@ def run_pair(pair: str, role_dir: Path) -> subprocess.Popen[bytes]:
         cmd,
         cwd=str(role_dir),
         env=env,
-        stdout=subprocess.PIPE,
-        stderr=subprocess.STDOUT,
         preexec_fn=os.setsid,
     )