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

Bumps [fastapi](https://github.com/fastapi/fastapi) from 0.132.0 to 0.135.2.
- [Release notes](https://github.com/fastapi/fastapi/releases)
- [Commits](fastapi/fastapi@0.132.0...0.135.2)

---
updated-dependencies:
- dependency-name: fastapi
  dependency-version: 0.135.2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

reference-apps/fastapi-api-first/requirements.txt

@@ -2,7 +2,7 @@
 # Must match code-first implementation versions for compatibility
 
 # Core FastAPI dependencies
-fastapi==0.132.0
+fastapi==0.135.2
 uvicorn[standard]==0.41.0
 pydantic-settings==2.13.1
 slowapi==0.1.9  # Rate limiting