Use TPA-maintained debian image
This is primarily to reduce usage of our dockerhub pull quota. See https://gitlab.torproject.org/tpo/tpa/team/-/wikis/service/ci#tpa-maintained-images
This is primarily to reduce usage of our dockerhub pull quota. See https://gitlab.torproject.org/tpo/tpa/team/-/wikis/service/ci#tpa-maintained-images