Examine slow-loading dependencies

## Summary

Some of Aruba's dependencies take a longish time to load. We pay for this time in every cucumber scenario. We should examine
whether we need each of them.

## Details

At least the following are 'slow'. Note: In normal use this would be insignificant, but in our tests this adds up, especially for JRuby:

- contracts
- tempfile

## Context & Motivation

Ongoing attempts to speed up the test suite.

Start by examining how Aruba dependencies are loaded for each Cucumber scenario, focusing on the reported contracts and tempfile dependencies. Measure their contribution to the test suite, especially under JRuby, and determine whether each is needed. Done means the unnecessary loading is removed or the investigation documents why each dependency remains and shows the resulting suite impact.

Written by the indexing model from the issue text.