[core/ FEAT] Add the possibility to push custom tags using PreTrainedModel itself (#28405)

* v1 tags

* remove unneeded conversion

* v2

* rm unneeded warning

* add more utility methods

* Update src/transformers/utils/hub.py

Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

* Update src/transformers/utils/hub.py

Co-authored-by: Lucain <lucainp@gmail.com>

* Update src/transformers/utils/hub.py

Co-authored-by: Lucain <lucainp@gmail.com>

* more enhancements

* oops

* merge tags

* clean up

* revert unneeded change

* add extensive docs

* more docs

* more kwargs

* add test

* oops

* fix test

* Update src/transformers/modeling_utils.py

Co-authored-by: Omar Sanseviero <osanseviero@gmail.com>

* Update src/transformers/utils/hub.py

Co-authored-by: Lucain <lucainp@gmail.com>

* Update src/transformers/modeling_utils.py

* Update src/transformers/trainer.py

Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

* Update src/transformers/modeling_utils.py

Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

* add more conditions

* more logic

---------

Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>
Co-authored-by: Lucain <lucainp@gmail.com>
Co-authored-by: Omar Sanseviero <osanseviero@gmail.com>

tests/test_modeling_utils.py

@@ -1435,6 +1435,11 @@ class ModelPushToHubTester(unittest.TestCase):
         except HTTPError:
             pass
 
+        try:
+            delete_repo(token=cls._token, repo_id="test-dynamic-model-with-tags")
+        except HTTPError:
+            pass
+
     @unittest.skip("This test is flaky")
     def test_push_to_hub(self):
         config = BertConfig(
@@ -1522,6 +1527,28 @@ The commit description supports markdown synthax see:
         new_model = AutoModel.from_config(config, trust_remote_code=True)
         self.assertEqual(new_model.__class__.__name__, "CustomModel")
 
+    def test_push_to_hub_with_tags(self):
+        from huggingface_hub import ModelCard
+
+        new_tags = ["tag-1", "tag-2"]
+
+        CustomConfig.register_for_auto_class()
+        CustomModel.register_for_auto_class()
+
+        config = CustomConfig(hidden_size=32)
+        model = CustomModel(config)
+
+        self.assertTrue(model.model_tags is None)
+
+        model.add_model_tags(new_tags)
+
+        self.assertTrue(model.model_tags == new_tags)
+
+        model.push_to_hub("test-dynamic-model-with-tags", token=self._token)
+
+        loaded_model_card = ModelCard.load(f"{USER}/test-dynamic-model-with-tags")
+        self.assertEqual(loaded_model_card.data.tags, new_tags)
+
 
 @require_torch
 class AttentionMaskTester(unittest.TestCase):