add the minimum support in torch-tensorrt when testing.

Author: GdoongMathew

requirements/pytorch/test.txt

@@ -17,3 +17,5 @@ fastapi  # for `ServableModuleValidator`  # not setting version as re-defined in
 uvicorn  # for `ServableModuleValidator`  # not setting version as re-defined in App
 
 tensorboard >=2.9.1, <2.21.0  # for `TensorBoardLogger`
+
+torch-tensorrt >=1.4.0; platform_system == "Linux"