GPU memory issues

[bittremieux]

As reported via email:

Regarding ANN-SoLo, I've found that there are some errors when using recent Faiss (v1.7.0+) with ANN-SoLo. I get out of GPU memory errors regardless of batch size (the same configuration in Faiss v1.6.5 had no problem at all).

TODO: Investigate this issue.