Merge branch 'feature/gb/enable-cross-project-pipeline-triggers' into 'master'

Enable cross-project pipeline triggers by default

See merge request gitlab-org/gitlab-ee!9374

ee/changelogs/unreleased/feature-gb-enable-cross-project-pipeline-triggers.yml

+---
+title: Cross-project pipelines support in .gitlab-ci.yml
+merge_request: 9374
+author:
+type: added

ee/lib/ee/gitlab/ci/config/entry/jobs.rb

@@ -25,7 +25,7 @@ module EE
             end
 
             def cross_project_triggers_enabled?
-              ::Feature.enabled?(:cross_project_pipeline_triggers, default_enabled: false)
+              ::Feature.enabled?(:cross_project_pipeline_triggers, default_enabled: true)
             end
           end
         end