Enforce string-formatting with f-strings (#10980)

* First third

* Styling and fix mistake

* Quality

* All the rest

* Treat %s and %d

* typo

* Missing )

* Apply suggestions from code review

Co-authored-by: Lysandre Debut <lysandre@huggingface.co>

Co-authored-by: Lysandre Debut <lysandre@huggingface.co>

tests/test_tokenization_auto.py

@@ -101,9 +101,7 @@ class AutoTokenizerTest(unittest.TestCase):
             mapping = tuple(mapping.items())
             for index, (child_config, _) in enumerate(mapping[1:]):
                 for parent_config, _ in mapping[: index + 1]:
-                    with self.subTest(
-                        msg="Testing if {} is child of {}".format(child_config.__name__, parent_config.__name__)
-                    ):
+                    with self.subTest(msg=f"Testing if {child_config.__name__} is child of {parent_config.__name__}"):
                         self.assertFalse(issubclass(child_config, parent_config))
 
     @require_tokenizers