CI: Bump Python to 3.13 and mypy to 1.12 in mypy workflow

[Eclips4]

I think that we're ready to bump python to 3.12 in mypy workflow, from what I can see at python/mypy#15277, mypy almost supports 3.12 except for python/mypy#15313.

[sobolevn]

A big +1 from me :)

[Eclips4]

FYI: There is a PR which failed due to Python 3.11 in the mypy workflow: #125589

[JelleZijlstra]

Note that "supporting" a version in the mypy issue tracker is often a bit of a misnomer. Mypy has long supported running on Python 3.12 fine; it just may not necessarily have good support for type checking all new features in Python 3.12.

[JelleZijlstra]

We could even run it on 3.13 if we update to the latest mypy release (1.12).

[AlexWaygood]

(Mypy will still reject new-in-Python 3.12 features in some of the various directories it checks, even with this change, without changes such as the one Pablo is proposing to make to the mypy.ini file in #125589. And that's deliberate: we want to ensure that some of our build tools can be run on older versions of Python.)

[AlexWaygood]

You get to remove a type: ignore comment from Argument Clinic that we don't need anymore, now 😃

[AlexWaygood]

Thanks!

[Eclips4]

Do you think this should be backported to 3.13?

[AlexWaygood]

If it backports cleanly, it's nice to have a consistent "CI experience" between the actively maintained branches. But I also wouldn't spend too much time on it if it doesn't backport cleanly :-)

[miss-islington-app]

Thanks @Eclips4 for the PR 🌮🎉.. I'm working now to backport this PR to: 3.13.
🐍🍒⛏🤖

[miss-islington-app]

Sorry, @Eclips4, I could not cleanly backport this to 3.13 due to a conflict.
Please backport using cherry_picker on command line.

cherry_picker d83fcf8371f2f33c7797bc8f5423a8bca8c46e5c 3.13

[bedevere-app]

GH-125596 is a backport of this pull request to the 3.13 branch.

[Eclips4]

If it backports cleanly, it's nice to have a consistent "CI experience" between the actively maintained branches. But I also wouldn't spend too much time on it if it doesn't backport cleanly :-)

Talking about the 3.12 branch, I'm not sure if this should be done there. Running mypy on the 3.13 version may give false positives for the 3.12 version, so... what do you think?

[AlexWaygood]

Talking about the 3.12 branch, I'm not sure if this should be done there. Running mypy on the 3.13 version may give false positives for the 3.12 version, so... what do you think?

As long as the python_version field is set to 3.12 or less in all the mypy.ini files on the 3.12 branch, it shouldn't theoretically be an issue to backport it to the 3.12 branch

[miss-islington-app]

Thanks @Eclips4 for the PR 🌮🎉.. I'm working now to backport this PR to: 3.12.
🐍🍒⛏🤖

[miss-islington-app]

Sorry, @Eclips4, I could not cleanly backport this to 3.12 due to a conflict.
Please backport using cherry_picker on command line.

cherry_picker d83fcf8371f2f33c7797bc8f5423a8bca8c46e5c 3.12