⬆️ Bump pillow from 10.2.0 to 10.3.0 in /backend

Bumps [pillow](https://github.com/python-pillow/Pillow) from 10.2.0 to 10.3.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@10.2.0...10.3.0)

---
updated-dependencies:
- dependency-name: pillow
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>