gitlab-ci: Set package jobs dependencies to empty

The default is to include all artifacts, but we don't need any for
these jobs.

.gitlab-ci.yml

@@ -250,11 +250,13 @@ test:smoke:two-outputs:
       - $PKG_ONLY == "1"
 
 package:deb-debian-buster:
+  dependencies: []
   extends: .l5-build-debian-package
 
 package:deb-debian-buster:arm64:
   tags:
     - librem5:arm64
+  dependencies: []
   extends: .l5-build-debian-package
 
 package:deb-pureos-amber:
@@ -270,6 +272,7 @@ package:deb-pureos-amber:
     - apt-get -y build-dep .
     - apt-get -y install build-essential git
     - git submodule update --recursive
+  dependencies: []
   extends: .l5-build-debian-package
 
 autopkgtest-debian-buster-package: