I hit this when upgrading to Ubuntu 25.04 as that upgraded to Python 3.13. I'm running the various python projects I want in a venv. For the projects stuck on 3.12 I ended up building and installing it from source to my local directory (removing the unprefixed links for compatibility) as the ppa for Python ports doesn't (didn't?) support the latest Ubuntu.
I dislike using something like docker or conda as I don't want to install/use a separate distro just to be able to use a different version of Python. My setup is working well so far.
Everyone has there own preferences, but I'd look into uv if I were you. It allows you to specify the python version, and for scripts you can even specify the python version as part of the shebang
uv is literally the goat except I haven't able to make vllm work in uv for some reason. Though aside from that, I think I need to use shebang more because I don't use it as often right now.