In #42794 we added the ability to hide some configurations for database
tasks. This is useful if you want your application to connect to a
database but if it's a separate service not run any tasks against it.

After adding this functionality I realized that the `configs_for`
argument no longer makes sense. `include_replicas` would include all of
them but ones with `database_tasks: false` aren't necessarily replicas.

This change deprecates `include_replicas` in favor of `include_hidden`
which will display all configurations. When not passed, this will
continue to return all writing connections that we want to perform tasks
on.