fix: reduce duplication of setup process

[dlstadther]

Description

Motivation and Context

How has this been tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[dlstadther]

Github Actions doesn't appear to support checking out and setting up the environment once and allowing reuse across multiple jobs. Reuse is supported across steps within a job, but not across jobs.