Change: Deprecate `check --check-unused` and add further checks Since restic 0.12.0, it is expected to still have unused blobs after running `prune`. This made the `--check-unused` option of the `check` command rather useless and tended to confuse users. This option has now been deprecated and is now ignored. The `check` command now also warns if a repository is using either the legacy S3 layout or mixed pack files with both tree and data blobs. The latter is known to cause performance problems. https://github.com/restic/restic/issues/3295 https://github.com/restic/restic/pull/3730