add a test deploy to netlify on PRs

[atvaccaro]

Description

Deploy a test site to Netlify on PRs, so we have site previews without merges to main.

Type of change

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

How has this been tested?

see CI

Screenshots (optional)

[github-actions[bot]]

Preview url: https://PR-251--cal-itp-reports.netlify.app