Pynisher `1.0.0` will have backwards breaking changes

An update to `pynisher` will go to `v1.0.0` but have backwards breaking changes, the requirements will need to be upper-bounded but we will hold off until we get an okay. This would also break your current benchmarking experiments so perhaps we hold off until they are completed.

The issue names no file or test; start by locating where the pynisher dependency is declared and reviewing the benchmarking experiments referenced in the issue. Done means the dependency constraint accounts for the planned breaking release without disrupting those experiments.

Written by the indexing model from the issue text.