[RACTF-33] S3 Versioning

[Bottersnike]

When a new version of the static site is deployed, rather than purging S3, the new version of the site should be deployed alongside the old version, but versioned such that old copies can be purged later if needed.

Jira issue: RACTF-33

[thebeanogamer]

So the simple solution is to just remove -delete from the CI pipeline. This will stop files from being removed when deploys run, but will obviously mean that the bucket contents will keep growing. Provided it never goes beyond 5gb, we're fine though, and we can purge it occasionally.

S3 versioning is a thing, but what that actually means is that you can request an old version of a file, which would never happen in our deployment. That makes more sense for backups/unversioned file names.