build(deps-dev): bump syrupy from 4.7.2 to 4.8.0 in /backend

Bumps [syrupy](https://github.com/syrupy-project/syrupy) from 4.7.2 to 4.8.0.
- [Release notes](https://github.com/syrupy-project/syrupy/releases)
- [Changelog](https://github.com/syrupy-project/syrupy/blob/main/CHANGELOG.md)
- [Commits](syrupy-project/syrupy@v4.7.2...v4.8.0)

---
updated-dependencies:
- dependency-name: syrupy
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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