Mistral unit tests unintentionally install OpenStack actions

[Renat Akhmerov]

We've now finally moved OpenStack actions into mistral-extra. However, if we run Mistral unit tests and mistral-extra is installed on the same machine then Mistral unit tests unintentionally load OpenStack actions. It happens because the base unit test class goes through the setup.cfg entry points and loads everything: the built-in actions like std.echo and action generators that are specified in the setup.cfg of mistral-extra. We need to avoid that. OpenStack actions should be tested only within mistral-extra.

Most likely, the solution is to specify what entry points need to be handled in unit tests.

[Renat Akhmerov (rakhmerov)]

The mistral.tests.unit.base.BaseTest class now has this code in the method setUp():

        self.override_config(
            'load_action_generators',
            False,
            'legacy_action_provider'
        )

It was added by the patch https://review.opendev.org/#/c/746022/