We should version dynamically, and unify JVM and Python versions of project

[vreuter]

We should have a single-point-of-truth for the version of the software -- not only within each of the Scala / JVM and Python branches of the project, but also between them. For the python portion of this, setuptools as a build backend supports this, but we perhaps need a Poetry plugin to make this work, as we'd prefer to keep Poetry as the build backend. For unifying the JVM and the Python portions, though, we'll most likely need some sort of build script.

[vreuter]

Use sbt-buildinfo for the Scala/JVM part, to just have version managed in build.sbt, therefore that file as single-source-of-truth for the JVM part of the project