I've been lazily avoiding this for a while, but we're now past the official deadline for travis-ci.org shutdown. The support period has probably been somehow extended as the current build setup still works.

But things will eventually break so the move to travis-ci.com should be taken care of. My understanding of https://docs.travis-ci.com/user/migrate/open-source-repository-migration is that the move should not really change anything on our side, including still being able to use the service for free as an open-source project.