Fix resume_download future warning (#31007)

* Fix resume_download future warning

* better like this

* Add regression test

tests/test_configuration_utils.py

@@ -20,6 +20,7 @@ import sys
 import tempfile
 import unittest
 import unittest.mock as mock
+import warnings
 from pathlib import Path
 
 from huggingface_hub import HfFolder, delete_repo
@@ -306,3 +307,10 @@ class ConfigTestUtils(unittest.TestCase):
         self.assertTrue(config._has_non_default_generation_parameters())
         config = BertConfig(min_length=0)  # `min_length = 0` is a default generation kwarg
         self.assertFalse(config._has_non_default_generation_parameters())
+
+    def test_loading_config_do_not_raise_future_warnings(self):
+        """Regression test for https://github.com/huggingface/transformers/issues/31002."""
+        # Loading config should not raise a FutureWarning. It was the case before.
+        with warnings.catch_warnings():
+            warnings.simplefilter("error")
+            PretrainedConfig.from_pretrained("bert-base-uncased")