Suppressed UserWarning: TORCH_CUDA_ARCH_LIST (#3160)

### Changes

<!--- What was changed (briefly), how to reproduce (if applicable), what
the reviewers should focus on -->
TORCH_CUDA_ARCH_LIST warning is suppressed using
`torch.cuda.get_arch_list()`.

Please let me know, if any changes are required.

### Related tickets

<!--- Post the numerical ID of the ticket, if available -->
Solves issue #3141

nncf/torch/extensions/__init__.py

@@ -12,6 +12,7 @@
 import enum
 import os
 import textwrap
+import warnings
 from abc import ABC
 from abc import abstractmethod
 from multiprocessing.context import TimeoutError as MPTimeoutError
@@ -98,9 +99,11 @@ def get(self, fn_name: str) -> Callable:
 
             with extension_is_loading_info_log(self._loader.name()):
                 try:
-                    pool = ThreadPool(processes=1)
-                    async_result = pool.apply_async(self._loader.load)
-                    self._loaded_namespace = async_result.get(timeout=timeout)
+                    with warnings.catch_warnings():
+                        warnings.filterwarnings("ignore", message="TORCH_CUDA_ARCH_LIST is not set")
+                        pool = ThreadPool(processes=1)
+                        async_result = pool.apply_async(self._loader.load)
+                        self._loaded_namespace = async_result.get(timeout=timeout)
                 except MPTimeoutError as error:
                     msg = textwrap.dedent(
                         f"""\