theano has been mostly abandoned upstream since 2018. (The Aesara fork
is not abandoned, but includes interface changes including the import
name, so would break reverse dependencies not specifically altered for it.)
Its reverse dependencies are keras, deepnano and invesalius.
It is currently broken, probably by numpy 1.24 (#1027215), and the
immediately obvious fixes weren't enough
(https://salsa.debian.org/science-team/theano/-/pipelines).
Is this worth spending more effort on fixing, or should we just remove it?