Fix flakey a11y test

[nccshecodes]

This PR may not fix all issues with running pa11yci (see open issue links in references) as research indicates there is a bug.

Continuing before server launch complete

The sitemap "http://localhost:5000/sitemap.xml" could not be loaded
yarn run v1.22.10
error Command failed with exit code 1.
$ pa11y-ci --sitemap http://localhost:5000/sitemap.xml --sitemap-find https://shecodes.dev --sitemap-replace http://localhost:5000

This would cause a failure when trying to locate the sitemap to run tests against, which couldn't be found if the server was not yet up and running. I expected wait-on to resolve this but there is an open issue (see references link 1). Adding a manual wait to the github action has fixed this. Will revisit based on outcome of open issue. WIP - experimenting with wait time. Below 5 will intermittently fail.

npx: installed 88 in 4.777s

Puppeteer Errors (WIP)

pa11y-ci intermittently throws an error when running against the sitemap. See references links 3 and 4 which are investigating a bug.

There's a couple of issues I've seen:

• memory
• page crash

References

1. Can't make wait-on work in Github action(open - subscribed)
2. Pa11y example failing due to Phantom process died error (closed)
3. Page crash errors when running against a Jekyll site (open - will be closed by #570)
4. Puppeteer Error: Navigation failed because browser has disconnected! (subscribed)
5. Leveraging GitHub Actions and pa11y-ci with axe