Fix race condition in e2e login test

[marlonbaeten]

Possible solution for #991

The login form navigates to the setup page by default, where the success message appears. We now wait for this navigation to happen.

[github-actions]

Sigrid maintainability feedback

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.76%. Comparing base (18917fc) to head (c2a678f).

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1012   +/-   ##
=======================================
  Coverage   89.76%   89.76%           
=======================================
  Files         248      248           
  Lines       12987    12987           
  Branches     1318     1318           
=======================================
  Hits        11658    11658           
  Misses       1235     1235           
  Partials       94       94           

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