⬆️ Replace mdformat-frontmatter with mdformat-front-matters

[kdeldycke]

mdformat-frontmatter is not compatible with mdformat 1.0.0, and seems unmaintained.

This PR replace it with mdformat-front-matters, which is actively maintained by @KyleKing and is becoming the de-facto frontmatter plugin in the mdformat universe, because of its adoption by mdformat-mkdocs.

This PR addresses #45.

Also to align the requirements with its dependencies, this PR bump the minimal Python version from 3.9 to 3.10. As a bonus, I activated tests on Python 3.14 and 3.15-dev.

Relates to:

• Uncap mdformat < 0.8.0 requirement butler54/mdformat-frontmatter#37
• build: Remove upper cap on mdformat version butler54/mdformat-frontmatter#38
• KyleKing/mdformat-mkdocs@34f2544

[kdeldycke]

All tests are passing, this PR is ready to me merged upstream.

[KyleKing]

Looks good, thanks! I can approve, merge, and release once these comments are addressed

[KyleKing]

Thank you! LGTM!

[kdeldycke]

This PR is ready to be merged upstream.

Even if @KyleKing is still working on a bug fix for YAML indention at KyleKing/mdformat-front-matters#10, I think we are safe to merge this PR and release a new mdformat-myst. Maybe v0.3.0 or even v1.0.0. Who's got authority on that repository?

[KyleKing]

I have the power to keep the lights on! I'll squash and release 0.3.0 since this is more inline with a zero-ver minor bump

[kdeldycke]

Thanks @KyleKing for the merge! 🎉

[kdeldycke]

Just a side note: if I can find mdformat_myst 0.3.0 on PyPi, there is no tag in the repository and the GitHub release for 0.3.0 is missing.

[KyleKing]

It should be released? I'm seeing 0.3.0 in PyPi: https://pypi.org/project/mdformat_myst/0.3.0

It looks like this repository doesn't have automatic releases: https://github.com/executablebooks/mdformat-myst/actions/runs/19745551258/job/56579111943. I'll make the release now!