Switch to Python 3.13

[mathbunnyru]

Describe your changes

Issue ticket if applicable

Checklist (especially for first-time contributors)

• I have performed a self-review of my code
• If it is a core feature, I have added thorough tests
• I will try not to use force-push to make the review process easier for reviewers
• I have updated the documentation for significant changes

[mathbunnyru]

I don't plan to merge this now, but let's see how many things are broken

[mathbunnyru]

We depend on updating mamba to v2:
#2147

#15 9.104 error    libmamba Could not solve for environment specs
#15 9.104     The following packages are incompatible
#15 9.104     ├─ mamba <2.0.0 is installable with the potential options

[mathbunnyru]

If you are interested in making Python 3.13 work for these images, please help conda-forge to build missing packages, here is the current progress: https://conda-forge.org/status/migration/?name=python313

[mathbunnyru]

Python 3.13.1 has been released, so we're waiting for the packages to be compatible with 3.13.
When tests pass, I will merge this, but I have no idea if it will be soon.