The data they provide is a test set (not a training set) and is from https://tatoeba.org https://tatoeba.org which is in turn under the permissive CC-BY license

The data they provide is a test set (not a training set) and is from https://tatoeba.org https://tatoeba.org which is in turn under the permissive CC-BY license. You can use that data for anything you like, but you can't use the code in the GitHub repository for commercial purposes - that includes running it to train models. Academic code often used to be under licenses like this, though it's much less common now.