`before_scenario` and `parallel` options

Is it by design that `before_scenario` runs multiple times if `parallel` is greater than `1`? I'm trying to setup a single process which can be accessed by the parallel run scenarios so that I can test how processes scale under load. If this is by design I'll find a way to work around it, but it seems like maybe `before_scenario` should just run once for each scenario no matter the value of `parallel` 🤔

Review how the `before_scenario` hook is handled when the `parallel` option is greater than 1, then reproduce the multiple executions described in the issue. Determine the intended hook frequency for parallel scenarios and verify the behavior with a regression test; done means the documented or agreed execution semantics are consistently enforced.

Written by the indexing model from the issue text.