Wagtail 7.2 maintenance

[nickmoreton]

An update of testing matrix around Wagtail 7.2

Compatibility and testing matrix updates:

• Updated the GitHub Actions workflow matrix to include Python 3.14, Django 5.2, and Wagtail 7.x, while excluding incompatible combinations such as Python 3.14 with Django 4.2 and 5.1.
• Expanded the compatibility documentation in README.rst to list Python 3.14, Django 5.2 (LTS), and Wagtail 7.0, 7.1, 7.2.

Configuration and dependency updates:

• Updated pyproject.toml classifiers to include Django 5.2, Wagtail 7, and Python 3.14, reflecting support for these newer versions.
• Revised the tox.ini environment list to add testing environments for Python 3.14, Django 5.2, and Wagtail 7.x, and updated dependency constraints for these versions.
• Adjusted the Django dependency range in the interactive test environment to allow Django 5.2 as well as 5.1.

Additions

Removals

Changes

Testing

Screenshots

Notes

Todos

Checklist

• PR has an informative and human-readable title
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code follows the standards laid out in the development playbook
• Passes all existing automated tests
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future todos are captured in comments
• Visually tested in supported browsers and devices (see checklist below 👇)
• Project documentation has been updated (including the "Unreleased" section of the CHANGELOG)
• Reviewers requested with the Reviewers tool ➡️

Testing checklist

Browsers

• Chrome
• Firefox
• Safari
• Internet Explorer 8, 9, 10, and 11
• Edge
• iOS Safari
• Chrome for Android

Accessibility

• Keyboard friendly
• Screen reader friendly

Other

• Is useable without CSS
• Is useable without JS
• Flexible from small to large screens
• No linting errors or warnings
• JavaScript tests are passing