chore(deps): Bump python-multipart from 0.0.20 to 0.0.21

Bumps [python-multipart](https://github.com/Kludex/python-multipart) from 0.0.20 to 0.0.21.
- [Release notes](https://github.com/Kludex/python-multipart/releases)
- [Changelog](https://github.com/Kludex/python-multipart/blob/master/CHANGELOG.md)
- [Commits](https://github.com/Kludex/python-multipart/compare/0.0.20...0.0.21)

---
updated-dependencies:
- dependency-name: python-multipart
  dependency-version: 0.0.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements.txt

@@ -30,7 +30,7 @@ hysteria2-api==0.1.3
 # Web panel (FastAPI stack)
 fastapi==0.124.2
 Jinja2==3.1.6
-python-multipart==0.0.20
+python-multipart==0.0.21
 hypercorn==0.18.0
 pydantic==2.12.5
 pydantic-settings==2.12.0