ci: Migrate tracie tests done in shell script to pytest

Reimplementation of the tracie's self-tests using a pythonic test suit (pytest).

The new tracie/test.py module is almost a direct translation of the tests defined in the tracie/test.sh. This new implementation of the test provides a more common framework where define the tests. And allows a better introspection for the tests results and/or resulting errors.

This MR also adds python3-pytest as dependency for the built images and adapts the tracie-runner scripts to run the self-test using pytest.

Signed-off-by: Pablo Saavedra psaavedra@igalia.com

Reviewed-by: Andres Gomez agomez@igalia.com