Revert subprocess changes in file.py - use subprocess.run instead of manual Popen

Author: Saga4

codeflash/verification/test_runner.py

@@ -25,31 +25,7 @@ def execute_test_subprocess(
     """Execute a subprocess with the given command list, working directory, environment variables, and timeout."""
     with custom_addopts():
         logger.debug(f"executing test run with command: {' '.join(cmd_list)}")
-        # Use explicit pipe management to prevent FD leaks
-        proc = subprocess.Popen(
-            cmd_list, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE, cwd=cwd, env=env, text=True
-        )
-        try:
-            stdout, stderr = proc.communicate(timeout=timeout)
-            returncode = proc.returncode
-        except subprocess.TimeoutExpired:
-            proc.kill()
-            try:
-                stdout, stderr = proc.communicate(timeout=5)
-            except subprocess.TimeoutExpired:
-                proc.terminate()
-                stdout, stderr = "", "Process terminated due to timeout"
-            returncode = -1
-        finally:
-            # Ensure all pipes are closed
-            if proc.stdin:
-                proc.stdin.close()
-            if proc.stdout:
-                proc.stdout.close()
-            if proc.stderr:
-                proc.stderr.close()
-
-        return subprocess.CompletedProcess(cmd_list, returncode, stdout, stderr)
+        return subprocess.run(cmd_list, capture_output=True, cwd=cwd, env=env, text=True, timeout=timeout, check=False)
 
 
 def run_behavioral_tests(