Stabilize shell approval MCP test (#14101)

## Summary
- replace the Python-based file creation command in the MCP shell
approval test with native platform commands
- build the expected command string from the exact argv that the test
sends

## Why this fixes the flake
The old test depended on Python startup and shell quoting details that
varied across runners. The new version still verifies the same approval
flow, but it uses `touch` on Unix and `New-Item` on Windows so the
assertion only depends on the MCP shell command that Codex actually
forwards.

codex-rs/mcp-server/tests/suite/codex_tool.rs

@@ -54,23 +54,26 @@ async fn test_shell_command_approval_triggers_elicitation() {
 async fn shell_command_approval_triggers_elicitation() -> anyhow::Result<()> {
     // Use a simple, untrusted command that creates a file so we can
     // observe a side-effect.
-    //
-    // Cross‑platform approach: run a tiny Python snippet to touch the file
-    // using `python3 -c ...` on all platforms.
     let workdir_for_shell_function_call = TempDir::new()?;
     let created_filename = "created_by_shell_tool.txt";
     let created_file = workdir_for_shell_function_call
         .path()
         .join(created_filename);
 
-    let shell_command = vec![
-        "python3".to_string(),
-        "-c".to_string(),
-        format!("import pathlib; pathlib.Path('{created_filename}').touch()"),
-    ];
-    let expected_shell_command = format_with_current_shell(&format!(
-        "python3 -c \"import pathlib; pathlib.Path('{created_filename}').touch()\""
-    ));
+    let shell_command = if cfg!(windows) {
+        vec![
+            "New-Item".to_string(),
+            "-ItemType".to_string(),
+            "File".to_string(),
+            "-Path".to_string(),
+            created_filename.to_string(),
+            "-Force".to_string(),
+        ]
+    } else {
+        vec!["touch".to_string(), created_filename.to_string()]
+    };
+    let expected_shell_command =
+        format_with_current_shell(&shlex::try_join(shell_command.iter().map(String::as_str))?);
 
     let McpHandle {
         process: mut mcp_process,