v1.0.3: Reproducing v1.0 even more closely
Restore pointing APT repo to latest sid after installing Python libraries
so that python/Dockerfile at OpenDRR/opendrr-api can fetch
git 2.33 and git-lfs git-lfs 2.13.3 instead of
git 2.28 and git-lfs 2.11.0, either of which is buggy and causes add_data.sh to fail.
This restores the behaviour of the original opendrr/python-env (v1.0) image.