Use job summary to improve build output

Recently, GitHub released a new feature for workflows: [job summaries](https://github.blog/2022-05-09-supercharging-github-actions-with-job-summaries/).
The org-wide-files workflow that creates the PRs to the tracks is a perfect candidate for using this workflow I feel. It could output a table listing the repos and with a link to the created PR, as well as some additional metadata (whether or not the PR already existed, whether it is a track or tooling repo, etc.).