Mark test_buildout_bootstrap with pytest
Mark test_buildout_bootstrap with pytest

Pytest runs `BuildoutOnlineTestCase.setUpClass` despite skipping all
tests. Mark `test_buildout_bootstrap` with pytest to avoid running the
`setUpClass`.

Signed-off-by: Benjamin Drung <86a6db991ec5c1a96f98c92b98df9d547d7c8c84@ionos.com>

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt