Support spmd knn search

[ethanglaser]

Description

Fix errors that occur when calling kNN search (ie without responses result_option set). Uses result option indication of whether results are requested, and only runs this logic when it is (previously it was running in all cases because regressor and classifier use responses, but its not needed for search)

Corresponding sklearnex PR adding these interfaces to API: https://github.com/uxlfoundation/scikit-learn-intelex/pull/2557

Checklist to comply with before moving PR from draft:

PR completeness and readability

• [ ] I have reviewed my changes thoroughly before submitting this pull request.
• [ ] I have commented my code, particularly in hard-to-understand areas.
• [ ] I have updated the documentation to reflect the changes or created a separate PR with update and provided its number in the description, if necessary.
• [ ] Git commit message contains an appropriate signed-off-by string (see CONTRIBUTING.md for details).
• [ ] I have added a respective label(s) to PR if I have a permission for that.
• [ ] I have resolved any merge conflicts that might occur with the base branch.

Testing

• [ ] I have run it locally and tested the changes extensively.
• [ ] All CI jobs are green or I have provided justification why they aren't.
• [ ] I have extended testing suite if new functionality was introduced in this PR.

[ethanglaser]

/intelci: run

[ethanglaser]

/intelci: run

[ethanglaser]

/intelci: run

[Alexandr-Solovev]

In file included from cpp/oneapi/dal/algo/knn/backend/gpu/infer_kernel_brute_force_dpc.cpp:24: ./cpp/oneapi/dal/algo/knn/backend/gpu/infer_kernel_impl_dpc_distr.hpp:230:14: error: no matching member function for call to 'push_back' 230 | deps.push_back(copy_current_resp_event); | ~~~~~^~~~~~~~~ /usr/lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/bits/stl_vector.h:1283:7: note: candidate function not viable: 'this' argument has type 'const bk::event_vector' (aka 'const vectorsycl::event'), but method is not marked const 1283 | push_back(const value_type& __x) | ^ /usr/lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/bits/stl_vector.h:1300:7: note: candidate function not viable: 'this' argument has type 'const bk::event_vector' (aka 'const vectorsycl::event'), but method is not marked const

[Alexandr-Solovev]

/intelci: run

[ethanglaser]

/intelci: run ml-benchmarks set get-build=f098d02c-9afe-f1fe-b72e-a4bf010d0e2d

[ethanglaser]

latest CI with both branches: http://intel-ci.intel.com/f098d02c-9afe-f1fe-b72e-a4bf010d0e2d