fix topk tests

[michaelfeil]

This pull request includes several changes to the unit tests in libs/infinity_emb/tests/unit_test/test_engine.py to improve test coverage and simplify the code. The most important changes include modifying parameterized tests to focus on the torch engine, refactoring the reranking logic, and consolidating assertions for different top_n values.

Improvements to test coverage and simplification:

• libs/infinity_emb/tests/unit_test/test_engine.py: Modified test_async_api_torch to only test the torch engine.
• libs/infinity_emb/tests/unit_test/test_engine.py: Updated test_engine_reranker_torch_opt to always use InferenceEngine.torch and refactored the reranking logic to simplify the sorting and assertion steps. [1] [2]
• libs/infinity_emb/tests/unit_test/test_engine.py: Modified test_engine_reranker_top_n to only test the torch engine and consolidated assertions for different top_n values into a loop for better readability and maintainability. [1] [2]

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.73%. Comparing base (2351e26) to head (46da9c9).
Report is 1 commits behind head on main.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #406      +/-   ##
==========================================
- Coverage   79.00%   78.73%   -0.27%     
==========================================
  Files          39       39              
  Lines        3015     3015              
==========================================
- Hits         2382     2374       -8     
- Misses        633      641       +8     

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