build: bump python-multipart from 0.0.27 to 0.0.31 in /src/backend

Bumps [python-multipart](https://github.com/Kludex/python-multipart) from 0.0.27 to 0.0.31.
- [Release notes](https://github.com/Kludex/python-multipart/releases)
- [Changelog](https://github.com/Kludex/python-multipart/blob/main/CHANGELOG.md)
- [Commits](Kludex/python-multipart@0.0.27...0.0.31)

---
updated-dependencies:
- dependency-name: python-multipart
  dependency-version: 0.0.31
  dependency-type: direct:production
...

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

Author: dependabot[bot]

src/backend/pyproject.toml

@@ -22,7 +22,7 @@ dependencies = [
     "opentelemetry-instrumentation-openai==0.60.0",
     "opentelemetry-sdk==1.40.0",
     "python-dotenv==1.2.2",
-    "python-multipart==0.0.27",
+    "python-multipart==0.0.31",
     "uvicorn==0.46.0",
     "pylint-pydantic==0.4.1",
     "pexpect==4.9.0",

src/backend/requirements.txt

@@ -5,7 +5,7 @@ azure-monitor-opentelemetry==1.8.7
 azure-monitor-events-extension==0.1.0
 azure-identity==1.25.3
 python-dotenv==1.2.2
-python-multipart==0.0.27
+python-multipart==0.0.31
 opentelemetry-api==1.40.0
 opentelemetry-sdk==1.40.0
 opentelemetry-exporter-otlp-proto-grpc==1.40.0