Upgrade django-argcache compatibility baseline to Django 4.2 and migrate tests to GitHub Actions

[Copilot]

This PR moves the project from Django 3.2-era compatibility to a Django 4.x-supported baseline (targeting 4.2), including removal of API usage that breaks on Django 4, alignment of package metadata, and migration of test CI to GitHub Actions.

• Django 4 compatibility fixes

  • Removed deprecated providing_args from custom signal construction in src/signals.py to match Django 4 signal API.

• Dependency and support baseline update

  • Updated setup.py requirement from django>=3.0 to django>=4.2,<5.0.
  • Updated setup.py classifiers to reflect current support:
    • Added Framework :: Django :: 4.2
    • Added Python classifiers for 3.8, 3.9, 3.10, 3.11, and 3.12
    • Fixed AGPL classifier typo to License :: OSI Approved :: GNU Affero General Public License v3

• CI migration

  • Dropped legacy .travis.yml.
  • Added .github/workflows/tests.yml to run tests on push/pull_request.
  • Runs matrix jobs for Python 3.8–3.12 with Django 4.2.
  • Uses least-privilege workflow permissions (contents: read).
  • Executes tests via python runtests.py.

• Django 4 cleanup for project config/docs

  • Added DEFAULT_AUTO_FIELD = 'django.db.models.AutoField' in test settings to avoid Django 4 default PK warnings and preserve current model behavior.
  • Updated README URLconf example to modern Django URL APIs (re_path / django.urls import).

# before
from django.dispatch import Signal
cache_deleted = Signal(providing_args=['key_set'])

# after
from django.dispatch import Signal
cache_deleted = Signal()

[willgearty]

@copilot also add a GitHub Action workflow to run the tests. Something like this:

name: Tests

on:
  push:
    branches: [main, master]
  pull_request:

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
        django-version: ['4.2']
    name: Python ${{ matrix.python-version }} / Django ${{ matrix.django-version }}
    steps:
      - uses: actions/checkout@v4
      - name: Set up Python ${{ matrix.python-version }}
        uses: actions/setup-python@v5
        with:
          python-version: ${{ matrix.python-version }}
      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          pip install "django==${{ matrix.django-version }}.*"
          pip install .
      - name: Run tests
        run: ./runtests.py

[Copilot]

@copilot also add a GitHub Action workflow to run the tests. Something like this:

...

Added the workflow at .github/workflows/tests.yml with the requested Python (3.8–3.12) and Django 4.2 matrix, plus least-privilege token permissions and python runtests.py test execution. Addressed in commit 16ab579.

[willgearty]

@copilot

1. Drop .travis.yml

2. Tidy setup.py classifiers:

   • Add 'Framework :: Django :: 4.2'
   • Add 'Programming Language :: Python :: 3.X' entries matching the test matrix
   • Fix the pre-existing typo on the AGPL line: 'License :: OSI Approved :: License :: OSI Approved :: GNU Affero General Public License v3' should be 'License :: OSI Approved :: GNU Affero General Public License v3'

[Copilot]

@copilot

1. Drop .travis.yml
   ...

Done in 505ab2d: removed .travis.yml, added Framework :: Django :: 4.2, added Python classifiers for 3.8–3.12, and fixed the AGPL classifier string typo in setup.py.