Bump gunicorn from 20.1.0 to 22.0.0 in /model-engine

Bumps [gunicorn](https://github.com/benoitc/gunicorn) from 20.1.0 to 22.0.0.
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@20.1.0...22.0.0)

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

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

Author: dependabot[bot]

model-engine/requirements.in

@@ -26,7 +26,7 @@ deprecation~=2.1
 docker~=5.0
 fastapi~=0.110.0
 gitdb2~=2.0
-gunicorn~=20.0
+gunicorn~=22.0
 httptools==0.5.0
 json-log-formatter~=0.3
 kubeconfig~=1.1