docs/examples: remove gunicorn from uwsgi example (#4501)

Author: xrmx

docs/examples/fork-process-model/flask-uwsgi/requirements.txt

@@ -2,7 +2,6 @@ click==8.1.7
 Flask==2.3.3
 googleapis-common-protos==1.52.0
 grpcio==1.56.2
-gunicorn==22.0.0
 itsdangerous==2.1.2
 Jinja2==3.1.6
 MarkupSafe==2.1.3