Update DEFAULT_AUTO_FIELD setting in Django CI workflow (psycopg#1182)

* test(django): Remove DEFAULT_AUTO_FIELD setting

Refs django/django-docker-box#59

* test(django): use DEFAULT_AUTO_FIELD for LTS4 and LTS5

Not to be used from main on.

---------

Co-authored-by: Daniele Varrazzo <daniele.varrazzo@gmail.com>

Author: jacobtylerwalls

.github/workflows/3rd-party-tests.yml

@@ -138,8 +138,10 @@ jobs:
             pip_django: git+https://github.com/django/django.git#egg=Django
           - django_label: lts4
             pip_django: "'Django >= 4.2, < 4.3'"
+            default_auto_fields: 'DEFAULT_AUTO_FIELD = "django.db.models.AutoField"'
           - django_label: lts5
             pip_django: "'Django >= 5.2, < 5.3'"
+            default_auto_fields: 'DEFAULT_AUTO_FIELD = "django.db.models.AutoField"'
 
           # Test with min and max Python supported versions
           - django_label: lts4
@@ -242,8 +244,7 @@ jobs:
               "django.contrib.auth.hashers.MD5PasswordHasher",
           ]
 
-          DEFAULT_AUTO_FIELD = "django.db.models.AutoField"
-
+          ${{ matrix.default_auto_fields }}
           USE_TZ = False
           HERE