Require typing_extensions on Python < 3.13

[stefanor]

On newer Python releases, the typing module has all we need.

Fixes: #189

[github-actions]

Thank you for the PR! The changelog has not been updated, so here is a friendly reminder to check if you need to add an entry.

[semohr]

Sorry for the delay!

Could you elaborate on the reasoning behind working around installing typing_extensions as a dependency?

From experience, version checks like the ones introduced in this PR tend to become brittle and harder to maintain over time. The typing_extensions package is specifically meant to handle these compatibility differences, so ideally we shouldn’t need to encode Python version logic in the codebase itself.

My preference would be to add typing_extensions as a dependency and rely on it to manage the compatibility layer, rather than maintaining custom version checks.

[stefanor]

So, two things:

1. typing_extensions was an undeclared dependency of confuse. Obviously undeclared dependencies are a problem.

I could just add it, but it wouldn't be needed on newer releases, so I changed the imports to be more future-focussed. As soon as you drop support for 3.13, you can drop the dependency (and simplify the imports).

If you just want a dependency on typing_extensions that's fine with me.

In Debian, we'll probably continue to carry the patch to use typing, because we don't need to support the older releases.

[semohr]

If it’s beneficial on your side, I don’t mind the version gated dependency too much here. From beets perspective, we already depend on typing_extensions unconditionally, so in practice it doesn’t make a difference for us either way.

[semohr]

Left some small notes. The poetry lock needs an update too.