Bump python-multipart in /sample-apps/starlette-postgres-uvicorn

Bumps [python-multipart](https://github.com/Kludex/python-multipart) from 0.0.20 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@0.0.20...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]

sample-apps/starlette-postgres-uvicorn/poetry.lock

@@ -10,7 +10,7 @@ dependencies = [
     "asyncpg (>=0.30.0,<0.31.0)",
     "cryptography (>=44.0.0,<45.0.0)",
     "uvicorn (>=0.34.0,<0.35.0)",
-    "python-multipart (>=0.0.20,<0.0.21)",
+    "python-multipart (>=0.0.31,<0.0.32)",
 ]
 
 [build-system]