assert that ProxyTensorMode does not accidentally bake in constants (#83297)
I think this is a useful sanity assert; even though baking in constants incorrectly might not cause correctness issues, it will definitely cause unnecessary compilations, and can cause functionalization to error unnecessarily.
Confirmed that this would have tripped on resnet18 before the last PR
Pull Request resolved: https://github.com/pytorch/pytorch/pull/83297
Approved by: https://github.com/ezyang
