Isolate the hook pipe I/O timeout test from shell startup files (#44297)

Run `hook_drains_output_and_times_out_while_stdin_is_blocked` with
`cmd.exe /D /C` on Windows and `/bin/sh -c` elsewhere to keep user shell
startup files out of the test.

GitOrigin-RevId: 296e65cf76b74543e91c9ed9024ba2442e7e33af

codex-rs/hooks/src/engine/command_runner_tests.rs

@@ -262,6 +262,19 @@ time.sleep(30)
     let input_json = format!(r#"{{"padding":"{}"}}"#, "x".repeat(1024 * 1024));
     let (runtime, _result_receiver) = runtime();
 
+    // Keep user shell startup files out of the pipe I/O timeout test.
+    let runtime = runtime.reconfigured(if cfg!(windows) {
+        CommandShell {
+            program: "cmd.exe".to_string(),
+            args: vec!["/D".to_string(), "/C".to_string()],
+        }
+    } else {
+        CommandShell {
+            program: "/bin/sh".to_string(),
+            args: vec!["-c".to_string()],
+        }
+    });
+
     let result = timeout(
         Duration::from_secs(10),
         run_command(&runtime, &handler, command, env, &input_json, temp.path()),