Cleanups after migrating to a single IOCTL to invoke tests in kernel mode

[guhetier]

Description

Clean up now unused code / data tables after the recent kernel mode test invocation refactoring.
Also fixes a test removal that slipped through a previous PR.

Testing

CI

Documentation

N/A

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.97%. Comparing base (dbfcce1) to head (6b0f381).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5787      +/-   ##
==========================================
- Coverage   86.11%   84.97%   -1.14%     
==========================================
  Files          60       60              
  Lines       18729    18729              
==========================================
- Hits        16128    15915     -213     
- Misses       2601     2814     +213     

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