[core] Fix flickering progress bar due to overriden prints to StringIO (

ray-project#34735)

Some modules are using print() to string buffers, which we unnecessarily intercept and hide/unhide our tqdm bars for. This causes flickering in the progress bar.

python/ray/experimental/tqdm_ray.py

@@ -3,6 +3,7 @@
 import json
 import logging
 import os
+import sys
 import threading
 import uuid
 from typing import Any, Dict, Iterable, Optional
@@ -37,6 +38,11 @@ def safe_print(*args, **kwargs):
  By default, the builtin print will be patched to this function when tqdm_ray is
  used. To disable this, set RAY_TQDM_PATCH_PRINT=0.
  """
+
+ # Ignore prints to StringIO objects, etc.
+ if kwargs.get("file") not in [sys.stdout, sys.stderr, None]:
+ return _print(*args, **kwargs)
+
  try:
  instance().hide_bars()
  _print(*args, **kwargs)