CI: Move the {SRC,WORK}_DIR variables to a place where they will be visible to all jobs

.gitlab-ci.yml

@@ -11,14 +11,15 @@ stages:
     only:
         - main
         - merge_requests
+    variables:
+        SRC_DIR: $CI_PROJECT_DIR            # Where the sources are
+        WORK_DIR: $HOME/CI_$CI_PIPELINE_ID  # Where we will work, so that it's not erased
 
 .breaking_tests: &breaking_tests
     allow_failure: true
 
 variables:
     GIT_DEPTH: 10 # No need to clone all the history
-    SRC_DIR: $CI_PROJECT_DIR            # Where the sources are
-    WORK_DIR: $HOME/CI_$CI_PIPELINE_ID  # Where we will work, so that it's not erased
 
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