Bump python-multipart from 0.0.20 to 0.0.22 in /src/backend

Bumps [python-multipart](https://github.com/Kludex/python-multipart) from 0.0.20 to 0.0.22.
- [Release notes](https://github.com/Kludex/python-multipart/releases)
- [Changelog](https://github.com/Kludex/python-multipart/blob/master/CHANGELOG.md)
- [Commits](Kludex/python-multipart@0.0.20...0.0.22)

---
updated-dependencies:
- dependency-name: python-multipart
  dependency-version: 0.0.22
  dependency-type: direct:production
...

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

Author: dependabot[bot]

src/backend/pyproject.toml

@@ -26,7 +26,7 @@ dependencies = [
     "pytest-asyncio==0.24.0",
     "pytest-cov==5.0.0",
     "python-dotenv==1.1.1",
-    "python-multipart==0.0.20",
+    "python-multipart==0.0.22",
     "semantic-kernel==1.39.3",
     "uvicorn==0.35.0",
     "pylint-pydantic==0.3.5",