Support Wagtail 5.2+, Wagtail 6+, Python 3.12 and Django 5

[Morsey187]

This PR adds support for:

• Wagtail 6.0
• Wagtail 5.2
• Djangov5
• Pyhon 3.12

There was one fix needed for Wagtail v6.0 to resolve an import error Query model moved to wagtail.contrib.search_promotions, and I've included commits from #385 for added Python and Django coverage.

Notes

You can test individual environments with tox using:

tox -e py310-django42-wagtail60

[Morsey187]

Issue:
My local build wants to remove this field, although, I'm not sure why as the field looks to exist still
https://github.com/wagtail/wagtail/blob/main/wagtail/images/models.py#L246

Would be great if this could be tested by someone else locally, to see if migration changes are needed and/or requested.

[jams2]

Are you referring to the change below (line 330)? It's just removing the verbose name attribute, which seems to make sense as it matches the field name. If I run makemigrations against your branch I get the following output:

Migrations for 'testapp':
  testapp/migrations/0003_alter_blogpage_body_alter_customimage_file.py
    - Alter field body on blogpage
    - Alter field file on customimage

So it seems there's some changes that haven't been added to migrations. In the past, for projects with test apps in the past I've removed all the test app migrations and remade them fresh using the newest oldest supported versions of Django and Wagtail - you just need to run tox on all the envs to make sure the migrations don't fail on any particular version.

[Morsey187]

As discussed over slack, I've updated the migrations on django 4.2 and wagtail 5.2

[zerolab]

Can you add Python 3.12, Wagtail 6, and remove Wagtail 4 from PyPI classifiers https://github.com/torchbox/wagtail-grapple/blob/main/pyproject.toml#L17 ?