IVF-PQ tests: fix segfault when accessing empty lists#838

rapids-bot[bot] merged 2 commits intorapidsai:branch-25.06rapidsai/cuvs:branch-25.06from

achirkin:fix-tests-ivf-pq-list-empty-segfaultachirkin/cuvs:fix-tests-ivf-pq-list-empty-segfaultCopy head branch name to clipboard