DB schema generated by a migration may look different in rails 4 and 5 (because rails 5 may use different default values). For this reason it's important to explicitly set for which rails version a migration was written for. See https://stackoverflow.com/questions/35929869/activerecordmigration-deprecation-warning-asks-for-rails-version-but-im-no/35930912#35930912
On GitLab.com this migration could take about 3 minutes. Disabling the statement we know we have enough time to complete this. Fixes #25976
This adds a migration to remove unused services, where the properties are empty. As the properties are empty, those do not contain any settings or other information. Fixes #25727