DR preparation: python config

[AlexanderLanin]

Currently we are defining a repo-local pyproject.toml which extends bazel-bin/tools/ide_support.runfiles/_main/external/score_python_basics~/pyproject.toml

That setup is extremely annoying and fragile (details to be documented?!).
But it does allow a centrally managed pyproject.toml.

Alternatively we create a "blueprint" file, and sync it to all repos "automatically".
This will need a proof of concept implementation, to see how it could work.
Maybe in cicd-workflows as that seems like a central place.

Update: we actually need that solution for non bazel repos anyway. So we can look at bazel repos afterwards.