build(deps): bump numpy from 2.2.0 to 2.2.1 in /backend

Bumps [numpy](https://github.com/numpy/numpy) from 2.2.0 to 2.2.1.
- [Release notes](https://github.com/numpy/numpy/releases)
- [Changelog](https://github.com/numpy/numpy/blob/main/doc/RELEASE_WALKTHROUGH.rst)
- [Commits](numpy/numpy@v2.2.0...v2.2.1)

---
updated-dependencies:
- dependency-name: numpy
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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