"auto_genny_workload" test_control doesn't prepend the genny path anymore as the workloads can now live outside genny repo as well.

The perf,yml has auto_workload_path relative to genny. They need to be modified to be relative to cwd
https://github.com/mongodb/mongo/blob/8b0819392ff2eec2d50a3713546fa9a675265599/etc/perf.yml#L463
https://github.com/mongodb/mongo/blob/5e8446f92d4826cfe2e8b9082efd0fbd540a9718/etc/perf.yml#L463