Add benchmarks to the hats-tap CI workflow

[gitosaurus]

At present the benchmark stage is there but errors out every time because there is nothing configured and nothing to do. While the performance of the TAP server (separate from LSDB) is not a central concern, it would be good to see that stage pass, and perhaps better than completely removing it.

Removing it entirely is also acceptable, if this particular project has no performant code to guard.