Add manual trigger

Author: sarahchen6

.gitlab-ci.yml

@@ -888,6 +888,8 @@ verify_maven_central_deployment:
   rules:
     - if: '$POPULATE_CACHE'
       when: never
+    - when: manual
+      allow_failure: true
     # - if: '$CI_COMMIT_TAG =~ /^v[0-9]+\.[0-9]+\.[0-9]+$/'
     #   when: on_success
   script: