Bump gunicorn from 21.2.0 to 23.0.0

Bumps [gunicorn](https://github.com/benoitc/gunicorn) from 21.2.0 to 23.0.0.
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@21.2.0...23.0.0)

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

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

Author: dependabot[bot]

requirements.txt

@@ -1,6 +1,6 @@
 Flask==3.0.0
 Flask-SQLAlchemy==3.1.1
-gunicorn==21.2.0
+gunicorn==23.0.0
 psycopg2-binary==2.9.9
 
 black==23.10.0