Draft: .oniro-ci: publish rauc bundles for pi4 to hawkbit

This patch-set fixes several issues and inefficiencies related to bundle build process and starts publishing Raspberry Pi 4 builds to HawkBit.

.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: []
 
 # This job is currently used to customize the behavior in oniro and xts-acts.
 # It will be removed when that is safe to do so. It is not documented.