Python dependency: Update flask-socketio requirement

Updates the requirements on [flask-socketio](https://github.com/miguelgrinberg/flask-socketio) to permit the latest version.
- [Release notes](https://github.com/miguelgrinberg/flask-socketio/releases)
- [Changelog](https://github.com/miguelgrinberg/Flask-SocketIO/blob/main/CHANGES.md)
- [Commits](miguelgrinberg/Flask-SocketIO@v5.5.0...v5.6.0)

---
updated-dependencies:
- dependency-name: flask-socketio
  dependency-version: 5.6.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -28,7 +28,7 @@ Flask-Migrate==4.*
 Flask-Paranoid==0.*
 Flask-Security-Too==5.4.*; python_version <= '3.9'
 Flask-Security-Too==5.7.*; python_version > '3.9'
-Flask-SocketIO==5.5.*
+Flask-SocketIO==5.6.*
 Flask-SQLAlchemy==3.1.*
 Flask-WTF==1.2.*
 Flask==3.1.*