added job-rules back in

.gitlab-ci.yml

@@ -12,8 +12,8 @@ build-image:
         --dockerfile "${CI_PROJECT_DIR}/Dockerfile"
         --destination "${CI_REGISTRY_IMAGE}:latest"
         --build-arg CI_TOKEN=${CI_JOB_TOKEN}
-  # rules:
-    # - if: $CI_COMMIT_BRANCH == "main"
-    #   changes:
-    #     - Dockerfile
-    #     - .gitlab-ci.yml
+  rules:
+    - if: $CI_COMMIT_BRANCH == "main"
+      changes:
+        - Dockerfile
+        - .gitlab-ci.yml