If a Django project defines DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField" (which is the recommended configuration for new projects), it's going to generate two migrations for wagtail_vector_index and wagtail_vector_index.backends.pgvector (see below). By setting AppConfig.default_auto_field we prevent this.
If a Django project defines
DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
(which is the recommended configuration for new projects), it's going to generate two migrations forwagtail_vector_index
andwagtail_vector_index.backends.pgvector
(see below). By settingAppConfig.default_auto_field
we prevent this.