Deprecate TorchRuntimeClient, corresponding classes, and the tutorial

What is the expected enhancement?

The TorchRuntime program does not use primitives, so it will be removed soon. Before that we have to deprecate everything that is related to TorchRuntimeClient. This includes:

• The runtime package with two scripts, hookbase.py and torch_runtime_client.py
• The tutorial 06_torch_runtime.ipynb
• Other components if any

In case of the tutorial, I think, it is enough to add a text in bold in the beginning saying that the tutorial is deprecated, the corresponding runtime programs are deprecated and will be removed.

[1ucian0]

Its a min of 3 months which has to include two releases per current Qiskit deprecation policy for removal (item 3 there)

In principle, the depreciation policy applies to the module API (as the code included in the package), not to the service API. I would make sure qiskit-machine-learning code fails gracefully once the service is gone

[manoelmarques]

So for a minimum deprecation time, I believe the msg would be something like:

....is deprecated as of version 0.5.0 and will be removed next release..."

That would be the shortest period unless a bug fix release is released just to remove it. Then the period could be 1 week, 3 days, one weekend 😃 Another option is to just remove the code altogether and write in the release notes it has been removed. Since it is a service and not an api like mentioned above, the whole service would be gone.