fix: add env variable to disable production job

Nexus-Auto-DevOps.gitlab-ci.yml

@@ -21,6 +21,8 @@ staging:
 
 production_manual:
   rules:
+    - if: '$PRODUCTION_DISABLED'
+      when: never
     - if: '$CI_KUBERNETES_ACTIVE == null || $CI_KUBERNETES_ACTIVE == ""'
       when: never
     - if: '$INCREMENTAL_ROLLOUT_ENABLED'