Fix issues when the default id field is BigAutoField.
Review Request #14747 — Created Dec. 23, 2025 and updated — Latest diff uploaded
Django 6.0 changes the default type for automatically-added id fields to
useBigAutoFieldinstead ofAutoField. This change adds some compat
utilities to detect this, and updates tests to reflect the new types
that are used in this situation.
Ran unit tests.