[ REMOVE ] cloud simulator pages

[javabster]

Once the cloud simulator service has been removed, the following pages should be removed from docs:

• https://docs.quantum.ibm.com/verify/using-ibm-quantum-simulators
• https://docs.quantum.ibm.com/verify/cloud-based-simulators

Also remove the Test setup example from the IQP setup section on the start/install page.

depends on: https://github.com/Qiskit/documentation/issues/536