Minor improvements to group testing

This [paper](https://arxiv.org/abs/2302.11431) makes some minor improvements to group testing. They note themselves that this is still not better than permutation sampling, so implementing the improvements would only make some sense for the sake of completeness.

The issue references a paper on group testing improvements. First, locate the existing group testing implementation in the repository, likely in modules related to data valuation or sampling. Read the linked paper to understand the proposed improvements. Determine how to integrate these changes while ensuring they don't break existing tests. The goal is to implement the improvements for completeness, even though they may not outperform permutation sampling.

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