How to test PRs for the GitHub Actions workflow for deploying to GitHub Pages

[seanh]

After enabling Dependabot for GitHub Actions we got a burst of PRs from it updating the workflow for deploying to GitHub Pages: #3332, #3333, #3334, #3335. These shouldn't normally come so thick and fast, it's just because we just enabled Dependabot.

Anyway, I'm happy to try and review changes to this workflow but I thought I'd document here how to test them in case that's useful for any other developers.

1. You need a test site: just a simple GitHub repo containing a test Pelican site and a caller workflow for deploying it, just like it says in our docs. For example, this is my test site for the workflow.
2. Change the reference in your test site's caller workflow to reference the version of the workflow on the branch with the changes, e.g. uses: getpelican/pelican/.github/workflows/github_pages.yml@dependabot/github_actions/actions/setup-python-5.
3. Either commit this change to your test site's main branch and it'll automatically trigger a deployment, or commit the change to another branch and then go to your test site's /actions/workflows/pelican.yml page (for example this page on my test site) and use the web interface to manually trigger a deployment from the branch you committed the change to.
4. Either way, if the deployment succeeds and the logging output looks clean then the PR is good 👍