gitlab-ci: Avoid passing artifacts between completely unrelated stages

The introduction of stages in gitlab-ci had quite a unfortune side
effect that is described in the documentation [1]. The whole artifacts
path (in our case obj/) is passed from one stage to another by default,
which is causing very odd behavior as the previous results are only
partially overwritten by the new cmake command and can even lead to
execution of tests that are not supposed to run in particular job.

[1] https://docs.gitlab.com/ee/ci/yaml/#dependencies

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>

.gitlab-ci.yml

@@ -44,6 +44,8 @@ stages:
 .tests:
   extends: .build
   stage: test
+  # This is needed to prevent passing artifacts from previous stages
+  dependencies: []
   script:
     - cmake $CMAKE_OPTIONS $CMAKE_ADDTIONAL_OPTIONS .. &&
       make -j$(nproc) &&