[test] refactor tests with spawn (#3452)

* [test] added spawn decorator

* polish code

* polish code

* polish code

* polish code

* polish code

* polish code

tests/test_fx/test_tracer/test_torchaudio_model/test_torchaudio_model.py

@@ -3,12 +3,14 @@ import torch
 from packaging import version
 from torchaudio_utils import trace_and_compare
 
+from colossalai.testing import clear_cache_before_run
 from tests.kit.model_zoo import model_zoo
 
 
 # We cannot handle the tensors constructed with constant during forward, such as ``torch.empty(0).to(device=Proxy.device)``
 # TODO: We could handle this case by hijacking torch.Tensor.to function.
 @pytest.mark.skip
+@clear_cache_before_run()
 def test_torchaudio_models():
     torch.backends.cudnn.deterministic = True