chore(release): 2.6.8-rc.4

## [2.6.8-rc.4](https://github.com/AnotherStranger/docker-borg-backup/compare/v2.6.8-rc.3...v2.6.8-rc.4) (2025-04-16)

### Code Refactoring

* **deps:** update python docker tag to v3.13.3-alpine3.21 ([ed077de5](https://github.com/AnotherStranger/docker-borg-backup/commit/ed077de53b38c21ed0dd6a33953ee9cf449d8768))