SW-966: made the pulp build step manual, because we do not want to run it and...

SW-966: made the pulp build step manual, because we do not want to run it and waste cpu cylces each time we do a lofar commit (and nothing in pulpcode changes), and we do want to run it when we want to deploy.

.gitlab-ci.yml

@@ -123,6 +123,7 @@ build_pulp_docker_image:
     - cd pulp-dockers/lofar-pulp
     - docker build -t ci_lofar_pulp:$CI_COMMIT_SHORT_SHA .
   interruptible: true
+  when: manual
 
 
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