tests(live): add sanity tests against gdev live chain

The goal is to execute theses tests on a regular basis against the real gdev storage with a scheduled pipeline.

.gitlab-ci.yml

@@ -129,6 +129,7 @@ sanity_tests:
   rules:
     - if: $CI_PIPELINE_SOURCE == "schedule"
     - when: never
+  stage: tests
   script:
     - cargo sanity-gdev