Stabilize Bazel tests (timeout tweaks and flake fixes) (#17791)

codex-rs/exec-server/tests/exec_process.rs

@@ -153,9 +153,12 @@ async fn assert_exec_process_write_then_read(use_remote: bool) -> Result<()> {
         .start(ExecParams {
             process_id: process_id.clone().into(),
             argv: vec![
-                "/usr/bin/python3".to_string(),
+                // Use `/bin/sh` instead of Python so this stdin round-trip test
+                // stays portable across Bazel and non-macOS runners where
+                // `/usr/bin/python3` is not guaranteed to exist.
+                "/bin/sh".to_string(),
                 "-c".to_string(),
-                "import sys; line = sys.stdin.readline(); sys.stdout.write(f'from-stdin:{line}'); sys.stdout.flush()".to_string(),
+                "IFS= read line; printf 'from-stdin:%s\\n' \"$line\"".to_string(),
             ],
             cwd: std::env::current_dir()?,
             env_policy: /*env_policy*/ None,