Bugfix: Ignoring the s3.storage-class option for metadata when archive tier is specified

Restic now will save snapshot metadata to non-archive storage tier whatsoever,
this will help avoid issues when data is being saved to archive storage class.
It is not providing any support for cold storages in restic, 
only saving users from making backups unusable.

https://github.com/restic/restic/issues/4583
https://github.com/restic/restic/issues/3202