ATM: Remove redundant code

[tiferet]

This PR is the code cleanup made possible by the previous few PRs. As such, it has a lot of lines of change (mostly code deletion 🥳), but the changes are conceptually small. I tried to make the commits as clear as possible, tackling one piece of complexity reduction per commit, and explaining it in the commit comment. Commit-by-commit review warmly recommended 😄

Note that this PR is based on the branch tiferet/endpoint-filters, because that branch has not yet been merged and I don't want to see the commits from #11281 in this PR as well.

main code deletions / simplifications

• isOtherModeledArgument and isArgumentToBuiltinFunction contained the old logic for selecting negative endpoints for training. These can now be deleted, and replaced by a single base class that collects all EndpointCharacteristics that are currently used to indicate negative training samples: OtherModeledArgumentCharacteristic. This in turn lets us delete code from StandardEndpointFilters that effectively said that endpoints that are high-confidence non-sinks shouldn't be scored at inference time, either.
• FilteringReason is no longer being used and can be deleted.
• Delete CoreKnowledge and StandardEndpointFilters: All remaining functionality in CoreKnowledge and StandardEndpointFilters is only being used in EndpointCharacteristics, so it can be moved there as a small set of helper predicates.

Timing checks

• ✅ KPI timing experiment: https://github.com/github/codeql-dca-main/issues/8659
• ☑️ The local runtime of endpoint_large_scale/ExtractEndpointDataTraining remains like it was after the last PR that affected timing: About 5s.

Closeshttps://github.com/github/ml-ql-adaptive-threat-modeling/issues/2110

[kaeluka]

✅ Approve

This is the kind of PR where I'm extra glad we have CI checks: big surface, but not much new logic ;)

I'll give this a formal approval once the first PR is merged and this has been rebased; but I've done the review now and it all looks good to me. I've left one question for my own understanding.

[tiferet]

✅ Approve

This is the kind of PR where I'm extra glad we have CI checks: big surface, but not much new logic ;)

I'll give this a formal approval once the first PR is merged and this has been rebased; but I've done the review now and it all looks good to me. I've left one question for my own understanding.

I rebased this on top of the latest version of tiferet/endpoint-filters, so if #11281 requires no more changes you can now go ahead and approve this one too. Thank you!

[tiferet]

@kaeluka to merge this into main I had to remove a merge conflict due to a tiny comment change in CoreKnowledge.qll which gets deleted in this PR. So now I need you to re-approve this before I can merge it 😞

[tiferet]

@kaeluka to merge this into main I had to remove a merge conflict due to a tiny comment change in CoreKnowledge.qll which gets deleted in this PR. So now I need you to re-approve this before I can merge it 😞

@adityasharad Thank you! ❤️

@kaeluka Never mind! 😄