What should we add?

The GenericBackend.run() method emits a RuntimeWarning when it's called and qiskit-aer isn't installed. This is to inform users that the simulation will not include noise. This is useful for users, because it's not otherwise obvious that the simulation is ideal if the fallback backend of BasicSimulator is being used. However, when running unit tests we often don't install aer in some environments to save time or to explicitly test the BasicSimulator path. This ends up spamming the test logs with the warning message:

qiskit/providers/fake_provider/generic_backend_v2.py:348: RuntimeWarning: Aer not found using BasicSimulator and no noise

which provides no value. Normally the warning would only be shown once, but our test config changes the default filters so we see it on every call to run. We should adjust the base testing harness's filters so that we filter this warning from being displayed during the run.