build(deps): bump fastapi-pagination from 0.15.4 to 0.15.6 in /backend

Bumps [fastapi-pagination](https://github.com/uriyyo/fastapi-pagination) from 0.15.4 to 0.15.6.
- [Release notes](https://github.com/uriyyo/fastapi-pagination/releases)
- [Commits](uriyyo/fastapi-pagination@0.15.4...0.15.6)

---
updated-dependencies:
- dependency-name: fastapi-pagination
  dependency-version: 0.15.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]