refactor(train): use module-level HfApi import in push_checkpoint_to_hub

huggingface_hub is a core dependency; the in-function import was
unnecessary. Move HfApi to a module-level import and point the test
monkeypatches at lerobot.common.train_utils.HfApi.

src/lerobot/common/train_utils.py

@@ -15,6 +15,7 @@
 # limitations under the License.
 from pathlib import Path
 
+from huggingface_hub import HfApi
 from torch.optim import Optimizer
 from torch.optim.lr_scheduler import LRScheduler
 
@@ -297,8 +298,6 @@ def push_checkpoint_to_hub(
     timed-out or crashed run still leaves recoverable checkpoints on the Hub.
     The model repo is created idempotently.
     """
-    from huggingface_hub import HfApi
-
     api = HfApi()
     api.create_repo(repo_id=repo_id, repo_type="model", private=private, exist_ok=True)
     api.upload_folder(

tests/utils/test_train_utils.py

@@ -155,12 +155,10 @@ def test_load_training_state_skip_optimizer(tmp_path, optimizer, scheduler):
 
 
 def test_push_checkpoint_to_hub_creates_repo_and_uploads(tmp_path, monkeypatch):
-    import huggingface_hub
-
     ckpt = tmp_path / "010000"
     (ckpt / "pretrained_model").mkdir(parents=True)
     api = MagicMock()
-    monkeypatch.setattr(huggingface_hub, "HfApi", lambda *a, **k: api)
+    monkeypatch.setattr("lerobot.common.train_utils.HfApi", lambda *a, **k: api)
     push_checkpoint_to_hub(ckpt, "user/run", private=True)
     api.create_repo.assert_called_once()
     assert api.create_repo.call_args.kwargs["private"] is True
@@ -175,12 +173,10 @@ def test_push_checkpoint_to_hub_creates_repo_and_uploads(tmp_path, monkeypatch):
 
 
 def test_push_checkpoint_to_hub_defaults_to_hub_default_visibility(tmp_path, monkeypatch):
-    import huggingface_hub
-
     ckpt = tmp_path / "010000"
     (ckpt / "pretrained_model").mkdir(parents=True)
     api = MagicMock()
-    monkeypatch.setattr(huggingface_hub, "HfApi", lambda *a, **k: api)
+    monkeypatch.setattr("lerobot.common.train_utils.HfApi", lambda *a, **k: api)
     push_checkpoint_to_hub(ckpt, "user/run")
     api.create_repo.assert_called_once()
     assert api.create_repo.call_args.kwargs["private"] is None