python3-django-cors-headers: update to 4.9.0; add test.sh

python3-django-cors-headers: update to 4.9.0; add test.sh

Major changes since 3.10.0:

4.0:
- add CORS_ALLOW_PRIVATE_NETWORK setting for Local Network Access spec support
- add async middleware support, reducing overhead on async views
- remove deprecated CORS_REPLACE_HTTPS_REFERER and CorsPostCsrfMiddleware
- remove three header names from default allowed list (accept-encoding, dnt, origin)

4.3:
- fix access-control-allow-credentials header not being omitted on
  non-allowed responses

4.6:
- drop support for Django 3.2 through 4.1

4.9:
- add Django 6.0 support
- tighten validation of sequence-type settings (e.g. CORS_ALLOW_METHODS)

Add PYPI_SOURCE_NAME:=django_cors_headers as the 4.x sdist uses
underscores in the filename.

Signed-off-by: Alexandru Ardelean <redacted>