Powerful unsupervised domain adaptation method for dense retrieval. Requires only unlabeled corpus and yields massive improvement: "GPL: Generative Pseudo Labeling for Unsupervised Domain Adaptation of Dense Retrieval" https://arxiv.org/abs/2112.07577
modified: environment.yml:modified: setup.py: Requires ees>=0.0.9 (where the bug of returning nothing from ES is solved)