Update environment

[wwarriner]

Pull Request

Intent

Bring build and dev environments up-to-date and separate dev from build.

Proposed Changes

• update ruff to 0.15.6
• update markdownlint to 0.21.0
• update yamllint to 1.38.0
• update all workflow actions to match new versions
• update pre-commit to match new versions
• update build package versions
• separate build and dev dependencies into pip requirements files
• clean up cruft

Changes to Section Headers

N/A

Changes to Page URLs

N/A

Related or Fixed Issues

N/A

Accessibility Checklist

I have ensured all of the following for new or changed content:

• all images have appropriate alt text. Guidelines
• all images with text have sufficient contrast ratio. Checker
• all image text is transcribed or described in body text.
• all technical terms, jargon, and abbreviations are introduced before they are used.

Style Checklist

I have done all of the following:

• searched for other relevant pages and crosslinked from my content to them.
• searched for other relevant pages and crosslinked from them to my content.
• added redirects in mkdocs.yml for any moved headers or pages.
• defined new technical terms, jargon, and abbreviations in the glossary.
• searched for existing technical terms, jargon, and abbreviations in the glossary and added crosslinks to them.
• properly formatted and introduced key branding terms. List here.

[wwarriner]

Move into pip requirements file

[Premas]

Everything else looks good to me.