Use ubuntu-24.04 instead of ubuntu-latest

[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]

Why I want to use explicit tag:

• consistent with aarch64 runners (there is no ubuntu-latest-arm-like tag at the moment)
• we control when we switch, no bizarre situation when suddenly start building everything on new runners without even knowing about it
• no warnings like https://github.com/jupyter/docker-stacks/actions/runs/12788007366 (having 67 warnings makes me to ignore them completely)
• explicit is better than implicit

Downside:

• need to make one more commit every 2 years :)

I don't think is gonna affect images in any way, but it's nice to be in control of how we build our images.