Because when git-annex lacks S3 version IDs for files stored in the bucket,
deleting them would cause data loss.
Also because git-annex is not able to download unversioned objects from a bucket
when versioning=yes.
This also prevents setting versioning=no. While that would perhaps be
possible to do safely, it would add complexity, and would mean that if
the user accidentially did enableremote versioning=no, they would not be
able to undo it.
This commit was sponsored by Trenton Cronholm on Patreon.
bb9817ceae