build(deps): bump greenlet from 3.3.0 to 3.3.1 in /backend

Bumps [greenlet](https://github.com/python-greenlet/greenlet) from 3.3.0 to 3.3.1.
- [Changelog](https://github.com/python-greenlet/greenlet/blob/master/CHANGES.rst)
- [Commits](python-greenlet/greenlet@3.3.0...3.3.1)

---
updated-dependencies:
- dependency-name: greenlet
  dependency-version: 3.3.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]