pytest-postgresql 3.1.3 and pytest-redis 2.4.0 added support for
pytest >= 7 so we can now drop the pytest pinning.

Tests still pass and it aligns the test requirements with other
swh modules.

Related to T3916

3.0 breaks backwards compatibility, we should handle the upgrade in a
separate patch, for now this ensures the rest of the pipelines can keep
running.

This adds the tools and the last 2 scripts to demonstrate how to start testing the
migration scripts.

This is a preparatory work for testing the keycloak migration.

Related to T2858

Needs djangorestframework-stubs>=1.4 for proper mypy checking.

so the scheduler interaction code is executed.

Note that this does not test for correctness in these interactions yet.

also move tests/__init__.py content in tests/conftest.py and adapt test code
accordingly.

This also ensures retries_left is set otherwise tests may fail when using
the local sheduler.

Current djangos-stubs version (1.2.0) is not compatible with latest mypy one (0.750).
So pin their version until the issue is fixed.

That also fix the pytest tests run

We do use the pytest-django plugin to manage the django db setup magic,
so with this change, we can run tests without an existing db, or starting
a postgres db dedicated to the tests using pifpaf.

related to T1261

This does the dependencies declaration the same way the
python3-swh.lister package does it.