add Django 5.0 support

[stefano-esubasta]

upon trying to test this project on Django 5.0, only test_validation_filters failed; after fixing it, everything seems to be working. hope this helps!

[WhyNotHugo]

Thanks!

[WhyNotHugo]

Looks like this fails on Python 3.9: https://github.com/WhyNotHugo/django-afip/actions/runs/8942289677/job/24640657514?pr=209#step:7:228

[stefano-esubasta]

yeah, sorry, my bad. looks like it's failing for django < 5.0. i'll refactor the test to check django's version before adding the aria-label attribute.

[WhyNotHugo]

Thanks!