allow null arg_inputs if kwarg_inputs is set

[technillogue]

Description

Currently, a module cannot be compiled if it is called with only kwarg inputs, because arg_inputs must not be none. This prevents some usages of MutableTorchTensorRTModule. arg_inputs should be allowed to be None if kwarg_inputs is not none.

Fixes # (issue)

Type of change

Please delete options that are not relevant and/or add your own.

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the style guidelines of this project (You can use the linters)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas and hacks
• I have made corresponding changes to the documentation
• I have added tests to verify my fix or my feature
• New and existing unit tests pass locally with my changes
• I have added the relevant labels to my PR in so that relevant reviewers are notified

[peri044]

Can you also change it here ? https://github.com/pytorch/TensorRT/blob/main/py/torch_tensorrt/dynamo/_compiler.py#L671-L672