Support for new Qiskit V2 primitives

[jf-kong]

The current implementation seems to be based on the V1 primitives and APIs of Qiskit. Qiskit has transitioned to V2 primitives with the release of Qiskit 1.0, and has deprecated the old APIs. There seems to be some changes to the backend too and code based on the old APIs may break. Are there plans to transition to the new APIs?

[mho291]

I just wrote a piece of code for the qiskit_client.py with Qiskit's V2 primitives. Haven't done the tests yet. Replying to this chat so we don't do double work.