fix: useTableSorting tests fails randomly, causing PR check to fail

[Jondyr]

Description

useTableSorting tests failed randomly (around once per 10 test runs for me locally). This is likely because useTableSorting's useEffect was not properly waited for. Changed waitFor to act.

Example of PR check failing:
https://github.com/Altinn/altinn-studio/actions/runs/11014485052/job/30585221160?pr=13573

tested locally with:
(for i in {1..100}; do (yarn test --ci useTableSorting.test.tsx)&; done);

Related Issue(s)

Verification

• Your code builds clean without any errors or warnings
• Manual testing done (required)
• Relevant automated test added (if you find this hard, leave it and we'll help out)

Documentation

• User documentation is updated with a separate linked PR in altinn-studio-docs. (if applicable)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.24%. Comparing base (49d1da7) to head (df831e2).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #13631   +/-   ##
=======================================
  Coverage   95.24%   95.24%           
=======================================
  Files        1502     1502           
  Lines       20581    20581           
  Branches     2492     2492           
=======================================
  Hits        19603    19603           
  Misses        869      869           
  Partials      109      109           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[ErlingHauan]

Nice fix!

[framitdavid]

I added skip-release notes on this one since it's only "internal" code that is changed. 😊 Waiting for all PR checks to turn green before merging. Since it's a unit test that is fixed, no further manual testing is required. 👏

[framitdavid]

Great work! :)