Merge branch 'jhunt/fix-async-reset' of https://github.com/jjh42/pytorch-lightning into jhunt/fix-async-reset

Author: Borda

src/lightning/pytorch/plugins/io/async_plugin.py

@@ -13,7 +13,7 @@
 # limitations under the License.
 
 from concurrent.futures import ThreadPoolExecutor
-from typing import Any, Optional, TYPE_CHECKING
+from typing import TYPE_CHECKING, Any, Optional
 
 import torch
 from lightning_utilities.core.apply_func import apply_to_collection
@@ -81,7 +81,7 @@ def _save_checkpoint(*args: Any, **kwargs: Any) -> None:
     def teardown(self) -> None:
         """This method is called to close the threads."""
         if self._executor is None:
-            return None
+            return
         self._executor.shutdown(wait=True)
         self._executor = None
 
@@ -94,4 +94,4 @@ def teardown(self) -> None:
 def _clone_tensor(t: torch.Tensor) -> torch.Tensor:
     """Clones a tensor on the caller thread."""
     # detach to avoid autograd history and clone to take a point-in-time copy
-    return t.detach().clone()
+    return t.detach().clone()