Do we need asv?

[natestemen]

asv is a benchmarking tool that was added to mitiq last year [original infra PR, deploying data to web PR]. Benchmarking data is stored in the mitiq-bench repo, and displayed live at https://unitaryfund.github.io/mitiq-bench/. They are intended to track the performance of PEC + ZNE over time. That said, I'm afraid of two things:

1. They are too noisy to be useful. There are huge fluctuations in the error mitigation factor.
2. We aren't generally trying to improve the error mitigation performance of these techniques broadly over time.

As a result of these two, I don't think anyone is using the benchmarks. If this is the case, should we still have them?

[Misty-W]

My vote would be to remove asv.

[andreamari]

Fine to remove, also for me. Unless there is a way of making it more useful. But I don't see it.

[natestemen]

removed in #1960