test: update pytorch training py_version configuration

Author: Shibo Xing

tests/conftest.py

@@ -221,12 +221,14 @@ def mxnet_eia_latest_py_version():
 
 @pytest.fixture(scope="module", params=["py2", "py3"])
 def pytorch_training_py_version(pytorch_training_version, request):
-    if Version(pytorch_training_version) < Version("1.5.0"):
-        return request.param
+    if Version(pytorch_training_version) >= Version("1.13"):
+        return "py39"
     elif Version(pytorch_training_version) >= Version("1.9"):
         return "py38"
-    else:
+    elif Version(pytorch_training_version) >= Version("1.5"):
         return "py3"
+    else:
+        return request.param
 
 
 @pytest.fixture(scope="module", params=["py2", "py3"])