Remove CodeQL tasks duplicating injected ones

[jjonescz]

Follow up on #7253.

Currently official builds are getting stuck on CodeQL step: https://dnceng.visualstudio.com/internal/_build/results?buildId=2414766&view=results (interestingly, test run of #7253 didn't get stuck, not sure why)
Test run of an official build of this PR: https://dnceng.visualstudio.com/internal/_build/results?buildId=2414884&view=results
This is like a change done in roslyn-sdk to resolve the same problem: dotnet/roslyn-sdk@816cd02

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.48%. Comparing base (00071ec) to head (2522861).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7267      +/-   ##
==========================================
- Coverage   96.48%   96.48%   -0.01%     
==========================================
  Files        1442     1442              
  Lines      345212   345212              
  Branches    11345    11345              
==========================================
- Hits       333086   333073      -13     
- Misses       9252     9263      +11     
- Partials     2874     2876       +2