Add option to print path to K's Python dependency

[Baltoli]

When using kup-installed K to run Poetry-based projects, we need to point the Poetry virtual environment at a version of Python that's been installed by Nix; pyenv and the system Python don't have the correct headers / include paths to work with the Nix C++ compiler that builds the Python binding modules.

We should implement a kup command that just prints out the path to the Python derivation that K depends on. For example:

$ kup which-k-python
/nix/store/bc45k1n0pkrdkr3xa6w84w1xhkl1kkyp-python3-3.10.12/bin/python3

Then, projects that want to use kup for a Python-based semantics can run something like:

$ poetry env use --no-cache $(kup which-k-python)

to make sure that their project uses the right version of Python.

Related:

• Unable to run kllvm integration tests pyk#357
• kup installs an incompatible version of K #82

[Baltoli]

Fixed by: runtimeverification/k#3823