fix(nyz): disable pytorch1.9.0 in default setting

setup.py

@@ -48,7 +48,7 @@ setup(
         'requests>=2.25.1',
         'six',
         'gym>=0.20.0',  # pypy incompatible
-        'torch>=1.3.1,<=1.9.0',
+        'torch>=1.3.1,<=1.8.0',  # PyTorch 1.9.0 is available, but you need to do something like https://github.com/opendilab/DI-engine/discussions/81
         'pyyaml',
         'easydict==1.9',
         'tensorboardX>=2.1,<=2.2',