Bump gunicorn from 21.2.0 to 22.0.0 in /src/api

Bumps [gunicorn](https://github.com/benoitc/gunicorn) from 21.2.0 to 22.0.0.
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@21.2.0...22.0.0)

---
updated-dependencies:
- dependency-name: gunicorn
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

src/api/requirements.txt

@@ -6,6 +6,6 @@ jsonlines
 azure-search-documents
 python-dotenv==1.0.1
 azure-search-documents==11.4.0
-gunicorn==21.2.0
+gunicorn==22.0.0
 flask-cors==4.0.1
 ./whl/prompty-0.1.20240505.73211-py3-none-any.whl