gitlab-ci: factorize "variables" block

.gitlab-ci.yml

@@ -39,17 +39,20 @@ test:
   tags:
     - docker
 
-prepare-release:
-  image: debian:10
-  needs: [build]
-  rules:
-    - if: $CI_PIPELINE_SOURCE == "trigger"
+.release-vars:
   variables:
     PREFIX: '$PROJECT_URI/packages/generic/$PROJECT/$TAG'
     ARCHIVE_V5_NAME: '$PROJECT.$TAG-e5.tbz'
     ARCHIVE_V7_NAME: '$PROJECT.$TAG-e7.tbz'
     PACKAGE_V5_URI: '$PREFIX/$ARCHIVE_V5_NAME'
     PACKAGE_V7_URI: '$PREFIX/$ARCHIVE_V7_NAME'
+
+prepare-release:
+  image: debian:10
+  needs: [build]
+  rules:
+    - if: $CI_PIPELINE_SOURCE == "trigger"
+  extends: .release-vars
   script:
     - apt-get update
     - apt-get install -y curl
@@ -69,12 +72,7 @@ release:
   needs: [prepare-release]
   rules:
     - if: $CI_PIPELINE_SOURCE == "trigger"
-  variables:
-    PREFIX: '$PROJECT_URI/packages/generic/$PROJECT/$TAG'
-    ARCHIVE_V5_NAME: '$PROJECT.$TAG-e5.tbz'
-    ARCHIVE_V7_NAME: '$PROJECT.$TAG-e7.tbz'
-    PACKAGE_V5_URI: '$PREFIX/$ARCHIVE_V5_NAME'
-    PACKAGE_V7_URI: '$PREFIX/$ARCHIVE_V7_NAME'
+  extends: .release-vars
   script:
     - echo "Release job for tag $TAG"
   release: