Add deprecation warning

[kt474]

Summary

fixes #1042

Details and comments

[kt474]

@rathishcholarajan can you take a look

[kt474]

@renier

[mtreinish]

So I'm a bit confused here, what is the status of qiskit-ibm-provider if we're telling people to use the runtime client instead? They're not equivalent sets of functionality. I get you're adding an interface for doing backend.run() via the circuit runner, but is that all that's needed? What about the other IQX api functionality? Also what about the in progress PRs like: https://github.com/Qiskit/qiskit-ibm-provider/pull/365 ?

[kt474]

So I'm a bit confused here, what is the status of qiskit-ibm-provider if we're telling people to use the runtime client instead? They're not equivalent sets of functionality. I get you're adding an interface for doing backend.run() via the circuit runner, but is that all that's needed? What about the other IQX api functionality? Also what about the in progress PRs like: Qiskit/qiskit-ibm-provider#365 ?

@renier - also unsure about the exact plan for this repo qiskit-ibm-provider

[1ucian0]

I get you're adding an interface for doing backend.run() via the circuit runner, but is that all that's needed?

For reference https://github.com/Qiskit/qiskit-ibm-runtime/issues/459

[jyu00]

Putting on hold label back on. Like Matthew said we shouldn't deprecate this until there is a replacement.