[primer] Enable everything (#2288)

See if we pass all our repos with experimental string processing enabled.
Django probably needed:
- Ignores >= 3.8 only

We could support PEP440 version specifiers, but that would introduce the packaging module as a dependency that I'd like to avoid ... Or I could implement a poor persons version or vendor

Commit history before merge:
 * [primer] Enable everything
 * Add exclude extend to django CLI args for primer
 * Change default timeout to from 5 to 10 mins for a primer project
 * Skip string normalization for Django
 * Limit Django to >= 3.8 due to := operator