.oniro-ci: do not pull artifacts from previous stage when building bundles

This saves several gigabytes of traffic per build. Those artifacts
are automatically pulled due to being present in the previous stage.
Bundle is built from source, so no artifact is ever used.

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@huawei.com>

.oniro-ci/build-generic.yaml

@@ -313,6 +313,8 @@
   extends: .build-image
   variables:
     CI_ONIRO_JOB_ARTIFACTS: "*.raucb"
+  # Avoid pulling in any artifacts from the previous stage.
+  dependencies: []
 
 .build-zephyr-image:
   extends: .build-image