Revert "test: Add system tests for exercise administration"

[arkirchner]

The system test is unstable. Revert for now to allow the CI to pass.

Reverts #3008

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 70.08%. Comparing base (caccb8a) to head (beba994).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3065      +/-   ##
==========================================
- Coverage   70.18%   70.08%   -0.11%     
==========================================
  Files         215      215              
  Lines        6850     6850              
==========================================
- Hits         4808     4801       -7     
- Misses       2042     2049       +7     

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[christophblessing]

So I understand that the test is flaky.
Could we use other measures than removing it entirely? I'm thinking about retrying it or marking it as flaky.

[arkirchner]

Thanks for pushing me to check this more deeply. We recently switched from Chrome to Firefox in the CI. Reverting this fixed the issue.

We were switching to Firefox because there were issues with Chrome. They seem to be solved. We can switch back to Chrome.

Can you review: openHPI/codeharbor#2105 and #3067