Django-pg-zero-downtime-migrations

- fixed unique constraint creation with the `deferrable` parameter
- split CI into smaller jobs

- added django 5.1 support
- added python 3.13 support
- added postgres 17 support
- marked postgres 12 support as deprecated
- marked postgres 13 support as deprecated
- dropped django 3.2 support
- dropped django 4.0 support
- dropped django 4.1 support
- dropped python 3.6 support
- dropped python 3.7 support
- dropped `migrate_isnotnull_check_constraints` command

- changed `ADD COLUMN DEFAULT NULL` to a safe operation for code defaults
- changed `ADD COLUMN DEFAULT NOT NULL` to a safe operation for `db_default` in django 5.0+
- added the `ZERO_DOWNTIME_MIGRATIONS_KEEP_DEFAULT` setting and changed `ADD COLUMN DEFAULT NOT NULL` with this setting to a safe operation for django < 5.0
- added the `ZERO_DOWNTIME_MIGRATIONS_EXPLICIT_CONSTRAINTS_DROP` setting and enabled dropping constraints and indexes before dropping a column or table
- fixed `sqlmigrate` in idempotent mode
- fixed unique constraint creation with the `include` parameter
- fixed idempotent mode tests
- updated unsafe migration links to the documentation
- updated patched code to the latest django version
- updated test image to ubuntu 24.04
- improved README

- added idempotent mode and the `ZERO_DOWNTIME_MIGRATIONS_IDEMPOTENT_SQL` setting
- fixed django 3.2 degradation due to the missing `skip_default_on_alter` method
- improved README
- updated the release github action

- fixed deferred sql errors
- added django 5.0 support
- added python 3.12 support
- added postgres 16 support
- dropped postgres 11 support
- removed the `ZERO_DOWNTIME_MIGRATIONS_USE_NOT_NULL` setting
- marked the `migrate_isnotnull_check_constraints` command as deprecated

- added django 4.2 support
- marked django 3.2 support as deprecated
- marked django 4.0 support as deprecated
- marked django 4.1 support as deprecated
- marked postgres 11 support as deprecated
- dropped postgres 10 support
- updated the test docker image to ubuntu 22.04