Integrations test should be part of the pytest suite

We should reimplement the tests in `integration.py` to run under pytest using [pytest-regressions](https://github.com/ESSS/pytest-regressions) and [pytest-benchmark](https://github.com/ionelmc/pytest-benchmark). We also need to add [markers](https://docs.pytest.org/en/7.1.x/example/markers.html) to these tests to be able to run it only on certain environments.