chore(deps): bump fastapi in /reference-apps/fastapi

Bumps [fastapi](https://github.com/fastapi/fastapi) from 0.124.0 to 0.124.4.
- [Release notes](https://github.com/fastapi/fastapi/releases)
- [Commits](fastapi/fastapi@0.124.0...0.124.4)

---
updated-dependencies:
- dependency-name: fastapi
  dependency-version: 0.124.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

reference-apps/fastapi/requirements.txt

@@ -1,4 +1,4 @@
-fastapi==0.124.0
+fastapi==0.124.4
 uvicorn[standard]==0.38.0
 pydantic-settings==2.12.0
 slowapi==0.1.9  # Rate limiting