Simplify gitlab-ci.yml structure and have variables passed correctly

debian/gitlab-ci.yml

@@ -10,7 +10,7 @@ stages:
   - build
   - test
 
-.build: &build
+build package:
   stage: build
   image: registry.salsa.debian.org/salsa-ci-team/images/gbp
   cache:
@@ -37,11 +37,6 @@ stages:
     - du -shc ${WORKING_DIR}/* # Show total file size of artifacts. Must stay are under 100 MB.
     - mv ${CCACHE_TMP_DIR} ${CCACHE_WORK_DIR}
 
-build package stretch:
-  <<: *build
-  variables:
-    RELEASE: stretch
-
 # Autopkgtest must be disabled, because the test 'upstream' will be skipped and
 # thus the command returns exit code 2 and is considered failed by Gitlab CI.
 # Removing 'breaks-testbed' stanza from tests/control will result in that the
@@ -65,7 +60,7 @@ build package stretch:
 run lintian stretch:
   <<: *run_lintian
   dependencies:
-    - build package stretch
+    - build package
   variables:
     RELEASE: stretch
 
@@ -109,7 +104,7 @@ run lintian stretch:
 test upgrade stretch:
   stage: test
   dependencies:
-    - build package stretch
+    - build package
   image: debian:stretch
   artifacts:
     when: always