Log Message:
Update restic to 0.12.1, as requested in PR pkg/56465.

- Improve error handling for rclone and REST backend over HTTP2
- Fix terminal output redirection for PowerShell
- Treat an empty password as a fatal error for repository init
- copy failed to copy snapshots in rare cases
- backup --quiet no longer prints status information
- Fix crash of check --read-data-subset=x% run for an empty repository
- Fix fdopendir: not a directory error for local backend
- Print created new cache message only on a terminal
- Fix crash of backup --exclude='**'
- Fix possibly missing backup summary of JSON output in case of error
- Correctly handle download errors during restore
- Empty files now have size of 0 in ls --json output

- Add auto-completion support for fish
- SFTP backend now checks for disk space
- Add --keep-within-hourly option to restic forget
- Support filtering and specifying untagged snapshots
- Allow specifying limit of snapshots list
- Optimize read performance of mount command
- find --pack fallback to index if data file is missing