chore: Remove live update for study group dashboard

[arkirchner]

Live updates have been disabled for 5 years. Seems safe to remove.

Related to b2fc574

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 70.25%. Comparing base (c8710f2) to head (bc52f12).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3057      +/-   ##
==========================================
+ Coverage   70.08%   70.25%   +0.16%     
==========================================
  Files         215      213       -2     
  Lines        6850     6814      -36     
==========================================
- Hits         4801     4787      -14     
+ Misses       2049     2027      -22     

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[arkirchner]

I am sorry. I realized an issue. The WebSocket code is rendering the initial UI even if no messages are received. This needs to be moved out to visualize the user progress.

[MrSerth]

Thanks for working on this part and opening a PR early. I would kindly ask not to remove the dashboard and/or the live update features. For sure, they have been disabled for about five years and were not fully functional.

Resolving these issues has been (and still is) an item on my personal follow-up list. There is a local branch with some changes lying around that I would like to finalize soon.

Disabling the live updates occurred at the beginning of the COVID-19 pandemic at a time when we just launched a programming course on openHPI. At that time, we had some performance regressions, which ultimately led to a multi-year refactoring of the code execution workflow (and thus is part of our journey towards Poseidon). Due to the difficult times back then and the stress we experienced, we aimed to identify potential issues and disabled components not completely necessary for that course.

As I know today, disabling trigger_rfc_action_cable_from_comment was unnecessary, and this works fine. The trigger_working_times_action_cable is somewhat more expensive, and could benefit from an early return if no subscription is present. For this latter part, I have already made some further improvements.