This PR:

• Disables other testing workflows (I expect it will be the last pre-archive PR here, with the exception of a README update)
• Adds a backup of our Heroku database as it exists today to this repo (there is no sensitive data in this, it's just public data about feedstocks, datasets, etc.)
• Adds a workflow to demonstrate how to restore a database from the backup file, and that tests that the restored database contains the expected data