How and when to clean up old versions (parallel deployments)

Since we support the last 3 major versions, we need to have a way to delete the old archives when a new major version releases.

We'd need to:

• Delete the version branch
• Delete the attached pages deployment
• Something else...

We could automate this using a script that we'd run manually once a year. I was also thinking that we could hold off deleting the deprecated versions until X.3 is released in order to give users some time to upgrade.