[swarm] call support for groups feature always on – disable the ability to turn off call support for groups

A. Jami app

Settings, General, System, remove:

1. Experimental heading
2. (Experimental) Enable call support for groups

B. Jami documentation

Change the 🧪 (Experimental) to a ✓ at the intersection of Desktop and Group calls in the “Calling” section in “All features by client” webpage
https://docs.jami.net/en_US/user/all-features-by-client.html#calling

C. Iteration

Should this issue be added to Iteration “Jun 10, 2024 - Jun 23, 2024” https://git.jami.net/groups/savoirfairelinux/-/cadences/3/iterations/90 as based on “Call Swarm: full pass” jami-daemon#953?

This can help with user discovery and providing feedback.

Thank you