Bump torch from 2.0.1 to 2.2.0 in /backend/requirements (#1933)

Bumps [torch](https://github.com/pytorch/pytorch) from 2.0.1 to 2.2.0.
- [Release notes](https://github.com/pytorch/pytorch/releases)
- [Changelog](https://github.com/pytorch/pytorch/blob/main/RELEASE.md)
- [Commits](pytorch/pytorch@v2.0.1...v2.2.0)

---
updated-dependencies:
- dependency-name: torch
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

backend/requirements/model_server.txt

@@ -8,7 +8,7 @@ pydantic==2.8.2
 retry==0.9.2
 safetensors==0.4.2
 sentence-transformers==2.6.1
-torch==2.0.1
+torch==2.2.0
 transformers==4.39.2
 uvicorn==0.21.1
 voyageai==0.2.3